Watch: Nick Kyrgios plays illegal shot before eventually ousting champion Daniil Medvedev

• Kyrgios ends Medvedev's US Open reign with four-set win

• Australian up to his usual on-court tricks but says he is turning 'narrative' around on him

• Medvedev will lose world No 1 ranking following defeat

Eventful, unpredictable and – in the end – irresistible. That was Nick Kyrgios’s performance against world No 1 Daniil Medvedev on Sunday night, which has broken open the US Open draw and left several bookmakers quoting Kyrgios as their favourite to win the tournament.

Admittedly, Kyrgios still showed flashes of the sort of indiscipline that has dogged his career. He tossed his racket twice during the first-set tie-break, picked up a code violation for audible obscenity, and later wasted a point by coming around the net-post to hit a looping miscue off Medvedev’s racket that would otherwise have landed yards out. This was correctly called a “foul shot” by chair umpire Eva Asderaki, with Kyrgios heard asking courtside commentator Patrick McEnroe why he wasn't allowed to cross the court and hit the winner and telling his team he thought the shot was 'legal'.

But those occasional moments of madness were far exceeded by Kyrgios’s magnificent stroke play, which included delicious drop shots, venomous passes and the usual whipcrack serve. Apart from one brief energy lull after the first-set tie-break – which he won by 12 points to 10 – he made Medvedev look limited and pedestrian.

After Medvedev’s title defence had come to an end, he told reporters that it was like facing one of the Big Three. “[I have] played Novak, Rafa,” he said, after his 7-6, 3-6, 6-3, 6-2 defeat.

“They all play amazing. Nick today played kind of their level, in my opinion.”

Medvedev also said that he had felt unwell, perhaps as a result of America’s ubiquitous air-conditioning. “The thing is in USA I get sick one time for sure in the swing because the AC is just crazy. Even in the locker room, I don't know in Fahrenheit, but it’s probably like 68 degrees or something. I felt my throat a little bit today. I think that physically maybe that played a little bit of a role.”

In his own press conference, Kyrgios said that he had grown tired of underachieving. “When I was really struggling mentally, I was very selfish. I felt like, 'I feel bad, I don't want to play.’ Then I looked at the people closest to me and how much I was letting them down, and I didn't want to do that any more.

“I was like, ‘I feel like I've got so much left to give to the sport.’ I just trained hard. I just put my head down. Look, let's get in better shape, first of all. Let's see how it goes. Obviously winning helps. I've been winning a lot this year. The motivation has been there. It's easy to train. It's easier to wake up when things are going great.

“I feel like I'm making people proud now. I feel like there's not as much negative things being said about me. I just wanted to turn the narrative around. That's basically it. I just was feeling so depressed all the time, feeling sorry for myself. I just wanted to change that.”

The result means that Medvedev is sure to lose the world No 1 ranking after this tournament. He will be succeeded by one of three players, depending on how results fall from now on: Rafael Nadal, Carlos Alcaraz or Casper Ruud.

As for Kyrgios, he will face Russia’s Karen Khachanov in the fourth round after Khachanov overcame the dogged Spaniard Pablo Carreno Busta in five sets.

After that tight victory, Khachanov looked forward to his meeting with Kyrgios.

“Nick said himself that he doesn't recognise himself in how professional he is right now,” said Khachanov.

“I think Wimbledon [where Kyrgios lost to Novak Djokovic in four sets in the final] showed him what he's capable of.”

Kyrgios outclasses Medvedev, as it happened

03:37 AM

Thanks for joining

Another memorable night in New York. Kudos to Kyrgios for an outstanding display of all court tennis. Comisserations to Medvedev who will lose the No 1 ranking with this defeat.

Relive the match below and join Telegraph Sport for more coverage from the US Open tomorrow with British hope Cameron Norrie in action.

03:30 AM

Kyrgios reacts

03:16 AM

Kyrgios 7-6, 3-6, 6-3, 6-2 Medvedev* (*denotes next server)

Kyrgios forehand winner, 30-15. Big first serve by Kyrgios and Medvedev's return flies into the crowd, 40-15.

Kyrgios ace. GAME SET MATCH KYRGIOS!

Wow.

03:12 AM

Kyrgios* 7-6, 3-6, 6-3, 5-2 Medvedev (*denotes next server)

Medvedev is simmering right now. He is not happy at all. The defence of his title is coming to an end and he will also lose his world No 1 ranking.

Kyrgios backhand winner takes the game to deuce. But back-to-back aces from Medvedev keeps his hopes alive.

Kyrgios to serve for the match next.

03:09 AM

Kyrgios 7-6, 3-6, 6-3, 5-1 Medvedev* (*denotes next server)

Kyrgios ace to start the game, 15-0. He then makes a bad misjudgement by letting a Medvedev return go over his head and the ball drops in, 15-15.

Kyrgios volley into the net, 15-30. Medvedev backhand pass drifts just wide, 30-30. Kyrgios ace to hold and move a game away from the quarter-finals. Medvedev slams the ball against the backboard in frustration.

03:04 AM

Kyrgios* 7-6, 3-6, 6-3, 4-1 Medvedev (*denotes next server)

Too good from Kyrgios as he hits his 14th forehand winner, 30-30. Big point coming up.

Kyrgios gets a look at a second serve and punishes Medvedev with an off backhand which Medvedev then nets his forehand.

Kyrgios breaks. Unplayable tennis from the Australian as he attacks again and Medvedev crumbles.

03:01 AM

Kyrgios 7-6, 3-6, 6-3, 3-1 Medvedev* (*denotes next server)

Medvedev is standing much further back now to return Kyrgios' serve. And the Australian chooses to serve and volley on the opening two points and comes out on top.

Kyrgios double fault, 30-15. Kyrgios forehand wide, 30-30. Outrageous forehand return winner from Medvedev from so far back, 30-40. Kyrgios is handed a code violation for a audible obscenity.

Kyrgios ace saves break point, deuce. And he holds when Medvedev puts a forehand return long.

02:56 AM

Kyrgios* 7-6, 3-6, 6-3, 2-1 Medvedev (*denotes next server)

Kyrgios blasts a forehand winner past Medvedev, 15-15. He's hitting his forehand beautifully tonight. So clean and effortless.

Another good forehand by Kyrgios and Medvedev puts a backhand wide, 30-30. Another forehand barrage by Kyrgios and Medvedev puts a backhand long, break point.

The crowd sense this is a big point coming up as the noise rises. Medvedev backhand into the net and Kyrgios breaks. A world class game from Kyrgios.

02:52 AM

Kyrgios 7-6, 3-6, 6-3, 1-1 Medvedev* (*denotes next server)

Rapid service hold to love from Kyrgios.

02:50 AM

Fourth Set: Kyrgios* 7-6, 3-6, 6-3, 0-1 Medvedev (*denotes next server)

Fast start from Kyrgios as he forces Medvedev into a forehand error, 15-30. Medvedev ace, his 19th of the match, 30-30.

Kyrgios goes for a huge flat forehand but misses. Medvedev holds.

02:41 AM

Kyrgios 7-6, 3-6, 6-3 Medvedev* (*denotes next server)

Huge forehand winner down the line, his 43rd winner of the match, 15-0. He then follows it up with a doube fault and an ace, 30-15.

122mph first serve is unreturned by Medvedev. Two set points. Kyrgios drop shot, Medvedev reaches it but nets.

Kyrgios takes a two sets to one lead. Excellent fight back from the Australian.

02:38 AM

Kyrgios* 7-6, 3-6, 5-3 Medvedev (*denotes next server)

Medvedev holds easily to love with an ace. Kyrgios to serve for the third set next.

02:34 AM

Kyrgios 6-6, 3-6, 5-2 Medvedev* (*denotes next server)

Brilliant from Medvedev to place a backhand down the line for a winner, 30-15. He then blasts a cross court backhand winner, 30-30.

Kyrgios responds with a volley winner, 40-30. Big first serve by Kyrgios to hold.

02:31 AM

Kyrgios* 7-6, 3-6, 4-2 Medvedev (*denotes next server)

More all court tennis as he takes the ball early, comes into the net and finishes with a backhand volley winner, 15-15. Kyrgios is on fire now as he drills a backhand return winner down the line, 15-30.

Medvedev responds with a forehand pass, 30-30. Medvedev weathers that Kyrgios storm to hold when the Australian nets.

02:26 AM

Kyrgios 7-6, 3-6, 4-1 Medvedev* (*denotes next server)

Kyrgios is in the zone right now. Lovely drop volley winner, 30-0. He drops in a tweener first serve which lands out at 40-0.

Kyrgios backhand wide, 40-30. Kyrgios finds a timely first serve and Medvedev nets his return.

02:23 AM

Kyrgios* 7-6, 3-6, 3-1 Medvedev (*denotes next server)

Medvedev second serve zips off the line for an ace, 30-0. 125mph first serve ace, 40-0.

Brilliant cross court forehand winner from Kyrgios, 40-15. And she does it again, 40-30. Medvedev double fault, deuce.

Kyrgios approaches the net and Medvedev misses with a backhand down the line, break point. Kyrgios breaks.

He hits a deep backhand return and Medvedev nets his backhand. Remarkable turnaround.

02:19 AM

Kyrgios 7-6, 3-6, 2-1 Medvedev* (*denotes next server)

Kyrgios holds to 15 comfortably after that bizarre moment in the previous game which I'm still very baffled by.

02:16 AM

Kyrgios* 7-6, 3-6, 1-1 Medvedev (*denotes next server)

Medvedev nets a backhand volley on the stretch on the opening point, 15-15. Good attacking tennis from Kyrgios and he finishes with a forehand volley winner, 15-30.

Kyrgios slips over as he stretches for a backhand. He stays down for a while, Medvedev comes over to check on the Australian, who is thankfully OK, 30-30.

Crazy moment here. Kyrgios whips a running forehand down the line and Medvedev's effort goes into the air and is about to drop on his side of the court. But Kyrgios inexplicably crosses onto Medvedev's side of the court and hits the ball away before the ball bounces. That's a foul shot and Kyrgios loses what would have been a break point.

Medvedev holds.

02:09 AM

Third Set: Kyrgios 7-6, 3-6, 1-0 Medvedev* (*denotes next server)

Kyrgios starts the set with a service hold to 30. The Australian looks in a much better frame of mind.

02:03 AM

Kyrgios* 7-6, 3-6 Medvedev (*denotes next server)

Kyrgios runs around his backhand to whips a lovely forehand down the line for a winner, 30-15. Medvedev forehand into the net 30-30.

Kyrgios goes for it on his forehand return but just misses, 40-30. Set point.

Anxious looking forehand from Medvedev flies wide, deuce. Medvedev backhand clips the baseline and catches out Kyrgios, second set point.

Kyrgios forehand long and we are on set apiece.

01:58 AM

Kyrgios 7-6, 3-5 Medvedev* (*denotes next server)

Much better intensity from Kyrgios now. Medvedev backhand return long, 40-15. And Kyrgios holds after a big serve down the T.

01:55 AM

Kyrgios* 7-6, 2-5 Medvedev (*denotes next server)

Medvedev backhand into the net, 30-15. Then a backhand flies the long. This match has gone very flat all of a sudden.

But maybe Kyrgios will spark into life here as Medvedev makes another backhand error, 30-40.

Kyrgios flattens a forehand winner down the line and he gets one of the breaks back.

01:52 AM

Kyrgios 7-6, 1-5 Medvedev* (*denotes next server)

Kyrgios double fault, 15-30. Then a backhand into the net, 15-40.

Medvedev drills a backhand into Kyrgios feet and the Australian reply is wide.

The Australian has lost his focus and concentration.

01:47 AM

Kyrgios* 7-6, 1-4 Medvedev (*denotes next server)

12th ace by Medvedev to open the service game. But Medvedev is rushed into a forehand error, 15-30.

Medvedev backhand down the line, Kyrgios puts his forehand into the net.

Medvedev holds when Kyrgios' return goes long.

01:44 AM

Kyrgios 7-6, 1-3 Medvedev* (*denotes next server)

Kyrgios gets back on track with a hold to 15. The Australian hasn't been himself so far in this set, maybe that will wake him up a bit.

01:40 AM

Kyrgios* 7-6, 0-3 Medvedev (*denotes next server)

Back-to-back backhand errors from Kyrgios, 30-15. Kyrgios ace, 40-15. Medvedev nets a drop shot, 40-30.

Medvedev holds when Kyrgios slaps a forehand long.

01:36 AM

Kyrgios 7-6, 0-2 Medvedev* (*denotes next server)

Serve and volley from Kyrgios but Medvedev places a backhand down the line for a winner, 0-15. Kyrgios double fault, 0-30. Another Kyrgios double fault, 0-40.

Kyrgios saves the first break point. Then the second with a forehand winner. And then an ace. Deuce.

Three double fault of the game from Kyrgios, fourth break point. Rally of the match so far, great defence by both players but Kyrgios nets a backhand volley.

Medvedev breaks.

01:31 AM

Second Set: Kyrgios* 7-6, 0-1 Medvedev (*denotes next server)

As we wait for the second set, Kyrgios leaves for a change of clothes. Now Medvedev complains to the umpire about talking from Kyrgios' support box. He tells the umpire that he will stop playing if it happens one more time.

Nice little mental reset for Medvedev as he holds to love with an ace.

01:25 AM

Kyrgios 7-6 Medvedev - TIEBREAK

Medvedev backhand long, 10-9. Kyrgios backhand into the net, 10-10. He rages at his box, saying they should tell him where to serve.

Kyrgios drop shot and Medvedev nets his forehand, 11-10. Kyrgios slams his racket on the court again after his lob drifts long, 11-11. Unbelievable Kyrgios drop shot winner, 12-11. 

Medvedev forehand down the line goes long, 13-11. An incredible set of tennis.

01:19 AM

Kyrgios 6-6 Medvedev - TIEBREAK

Kyrgios forehand long, 6-7. Kyrgios steps in on a Medvedev second serve and flicks a backhand return down the line, brilliant shot, 7-7. Medvedev ace, 7-8. Stunning backhand volley winner by Kyrgios, 8-8.

Big Kyrgios first serve unreturned, 9-8. Medvedev ace, 9-9.

01:15 AM

Kyrgios 6-6 Medvedev - TIEBREAK

Medvedev ace, 4-3. 124mph Kyrgios ace, 5-3. Long rally, Medvedev keeps his nerve and Kyrgios nets a backhand, 5-4. Kyrgios backhand into the net, he slams his racket onto the ground in anger, 5-5. 

Kyrgios forehand return into the net, 5-6. Medvedev backhand return long, 6-6. 

01:10 AM

Kyrgios 6-6 Medvedev - TIEBREAK

Big first serve by Kyrgios, 1-0. Medvedev forehand zips past Kyrgios for a winner, 1-1. Kyrgios forehand return winner down the line, 2-1. Medvedev forehand into the net, 3-1. Kyrgios backhand volley winner, 4-1. Medvedev forehand winner, 4-2.

01:06 AM

Kyrgios* 6-6 Medvedev (*denotes next server)

Kyrgios is angry with himself after flicking a backhand long, 30-15. Kyrgios backhand return long, 40-15.

Good backhand return from Kyrgios puts Medvedev into trouble and the Australian's forehand down the line is too strong for the Russian.

But Medvedev does hold and we enter a tiebreak after 44 minutes.

01:03 AM

Kyrgios 6-5 Medvedev* (*denotes next server)

Kyrgios misjudges a Medvedev backhand return which drops well inside the baseline, 30-15. Medvedev backhand long, 40-15.

First Kyrgios blow up of the night as he rows with the umpire over when the serve clock is started. The Australian thinks umpire Eva Asderaki is starting it too quickly.

Kyrgios keeps his head to hold serve and secure a tiebreak at the very least for himself.

12:57 AM

Kyrgios* 5-5 Medvedev (*denotes next server)

Routine love hold from Kyrgios. Imperious serving.

12:53 AM

Kyrgios 5-4 Medvedev* (*denotes next server)

Medvedev guides a forehand winner down the line, 15-30. Big first serve by Kyrgios and he finishes with an overhead winner, 30-30.

Kyrgios whips a forehand winner into the corner, 40-30. And he holds with another ace which spins away from Medvedev's racket.

12:51 AM

Kyrgios* 4-4 Medvedev (*denotes next server)

128mph Medvedev ace, 15-15. Frustration for Kyrgios as he nets a backhand return, 30-15. 118mph Medvedev ace, 40-15.

Medvedev backhand winner to hold. All business from the Russian.

12:46 AM

Kyrgios 4-3 Medvedev* (*denotes next server)

Great defence by Medvedev, he drops a backhand pass at Kyrgios' feet and the Australian nets, 15-30. Medvedev then places a sensational backhand down the line, 15-40.

Kyrgios saves the first break point. But not the second as Kyrgios nets a backhand after another long rally.

Medvedev breaks back.

12:43 AM

Kyrgios* 4-2 Medvedev (*denotes next server)

Good patience by Kyrgios to stay in another long rally and this time Medvedev breaks, 15-15. Medvedev ace, 30-15.

Kyrgios forehand winner, 30-30. Kyrgios steps in on Medvedev second serve with his backhand return and earns the error. Break point. Kyrgios revs up the crowd.

Medvedev forehand wide and Kyrgios breaks.

12:37 AM

Kyrgios 3-2 Medvedev* (*denotes next server)

132mph ace from Kyrgios on the opening point, 15-0. Fifth ace from Kyrgios, 30-15. And he holds when Medvedev puts a backhand return long.

Very impressive serving from both players.

12:35 AM

Kyrgios* 2-2 Medvedev (*denotes next server)

Medvedev backhand winner to start the game, 15-0. Then a cross court backhand winner, 30-0.

Forehand winner to finish. Rapid service game from the Russian.

12:32 AM

Kyrgios 2-1 Medvedev* (*denotes next server)

Longest rally of the match, clean hitting from both, 20 shots but it is Kyrgios who cracks first with a forehand into the net, 0-15.

119mph Kyrgios second serve ace, 30-15. Followed by a double fault. Kyrgios finds a first serve down the T and Medvedev can't return it.

Forehand winner by Kyrgios to seal the game.

12:28 AM

Kyrgios* 1-1 Medvedev (*denotes next server)

Kyrgios backhand volley winner, 0-30. Medvedev responds with a wide ace, 15-30. Medvedev puts forehand long, two break points.

Medvedev takes the point to Kyrgios and finishes with a forehand winner. And he saves the second when Kyrgios' forehand return goes long.

Medvedev survives that early scare when Kyrgios puts another return long.

12:24 AM

First Set: Nick Kyrgios 1-0 Daniil Medvedev* (*denotes next server)

130mph ace down the T from Kyrgios to start the match, 15-0. And a 123mph ace to complete a hold to 15.

Great serving.

12:15 AM

Here we go!

Quick pre-match interview with both players, who say they want to put on a 'show'.

Kyrgios and Medvedev walk onto court on Arthur Ashe Stadium and get a warm reception from the crowd.

Medvedev wins the toss and opts to receive serve...

12:09 AM

US Open day 7 results

Men's Singles Fourth Round

Matteo Berrettini (13), Italy, beat Alejandro Davidovich Fokina, Spain, 3-6, 7-6 (2), 6-3, 4-6, 6-2.

Casper Ruud (5), Norway, beat Corentin Moutet, France, 6-1, 6-2, 6-7 (4), 6-2.

Women's Singles Fourth Round

Caroline Garcia (17), France, beat Alison Riske-Amritraj (29), United States, 6-4, 6-1.

Coco Gauff (12), United States, beat Zhang Shuai, China, 7-5, 7-5.

12:00 AM

Exclusive interview

Outspoken 24-time Grand Slam winner Margaret Court explains her tennis exile, Wimbledon snub and why her record will never be beaten.

Read more of her thoughts here.

11:46 PM

Medvedev on facing Kyrgios

11:35 PM

Kyrgios on facing Medvedev

11:21 PM

Good evening

Hello and welcome to arguably the match of the US Open so far in the men's draw as defending champion Daniil Medvedev takes on Wimbledon finalist Nick Kyrgios.

It promises to be a heavyweight showdown with both players in excellent form coming into the match. Intriguingly, Kyrgios has a 3-1 head-to-head lead against Medvedev and won their most recent meeting at in Montreal last month.

Medvedev said: "We both kind of know what to expect right now. He managed to get the better of me there (Montreal) for sure, especially I would say in terms of clutch moments.

"I kind of know what I have to do. Serve well, try to get to the tie-break, try to get opportunities on his serve. He also knows what he will do. He's playing good so far. I watched his matches. Concentrated. Definitely I'm looking forward to it. Hopefully I can play my best game."

Medvedev, who has made at least the semi-finals in the last three US Opens and is trying to become the first repeat champion since Roger Federer won five straight from 2004 to 2008. He is also the only player in the top half of the draw who has not lost a set and no man has won a US Open title without losing a set in the open era, which began in 1968.

After reaching the Wimbledon final in July, Kyrgios has maintained his level and is through to the fourth round in New York for the first time following a 6-4 6-2 6-3 victory over American JJ Wolf.

He said: "Win or lose, I'm proud of how far I've come. I've worked hard to be in the fourth round of the US Open. I think that's where every tennis player wants to be, playing the best players in the world in the best stadiums in the world, getting paid well. I'm looking forward to it."