US Open 2016: Kyle Edmund beats John Isner to reach fourth round

Britain's Kyle Edmund set up a US Open showdown with Novak Djokovic by beating John Isner to reach the fourth round of a Grand Slam for the first time.

The Briton, 21, overcame the big-serving American and 20th seed 6-4 3-6 6-2 7-6 (7-5) in two hours and 43 minutes on Court Louis Armstrong.

The world number 84 faces 2015 champion and top seed Djokovic on Sunday.

Djokovic reached the last 16 when a second successive opponent pulled out through injury at Flushing Meadows.

Edmund joined fellow Briton Johanna Konta in reaching the fourth round while compatriots Andy Murray and Dan Evans will on Saturday seek to join them in the last 16.

Edmund was beaten by Isner in straight sets at the French Open this year but his confidence has risen since he led Britain to Davis Cup victory, without Murray, over Serbia in July.

Isner, 31, fired down 27 aces but could only convert one of his seven break points as Edmund's serve held up under the pressure.

"It's been a great tournament so far," said Edmund, who knocked out world number 15 Richard Gasquet in the first round.

"I've really enjoyed playing here. It may not have been the result you guys wanted but I want to say thanks for the support."

Perhaps the key moment came when the American had just taken the second set and created three break points at the start of the third.

Edmund, however, saved all three and then broke twice himself, sealing the set when Isner failed to make a simple forehand volley.

Isner saved two match points in the fourth set tie-break, but a forehand winner confirmed Edmund's thrilling victory.

"Chances don't come very often against John. You have to capitalise when they do. You see how many aces he hits," he added.

"You just have to get a racquet on the ball and hustle really.

"I played the big points well. I knew it would come down to one or two points."

Djokovic will be a step up in class, but Edmund knows what to expect after losing to the Serb in Miami in March.

He may also seek advice from Murray, his compatriot and mentor, who knows the 12-time major champion's game as well as anyone.

"Playing the world number one is always going to be tough," Edmund said.

"He's rightfully world number one. He's been very consistent at a high level.

"I'll learn from what happened in Miami. Playing Isner at the French Open helped me tonight so maybe that will help me again."

BBC Sport tennis correspondent Russell Fuller

Edmund had only won one Grand Slam match before this year - but in the space of eight months has turned into a man capable of winning vital Davis Cup matches and reaching the second week of a Grand Slam.

Isner's long, drawn-out route to the third round caught up with him, but he showed great willpower to drag Edmund into a fourth set tie-break.

In turn, the 21-year-old showed great resilience to take his third match point, and control the tension that was coursing through his veins.

Djokovic, who had a walkover in the second round when Jiri Vesely conceded, was leading 4-2 when Russian Mikhail Youzhny quit with a leg problem.

"It's difficult to pick the words. I don't think I have had this situation before," said the top-seeded Serb.

Djokovic, who has been troubled by a wrist injury in recent months, was on court for only 32 minutes.

"Mikhail carried the injury into this match," said the 29-year-old, who went to the practice courts with coach Boris Becker immediately after his on-court interview.

"I will try to get the positives out of these six games. I started well with good intensity and will try to carry that on to the next match.

"I'm sorry you guys watching didn't get to see a full match."

Two-time US Open champion Rafael Nadal of Spain beat Russia's Andrey Kuznetsov 6-1 6-4 6-2 in the final men's match of the day.

Nadal, seeded fourth, has not dropped a set in reaching the last 16 of a tournament he won in 2010 and 2013.

"I had a fantastic first set, a little trouble with my serve in the second but the third was key so I'm very happy," said Nadal.

The 30-year-old next faces France's 24th-seeded Lucas Pouille, a 3-6 7-5 2-6 7-5 6-1 winner over Spain's Roberto Bautista Agut.

American 26th seed Jack Sock knocked out 2014 champion Marin Cilic.

Croat Cilic was affected by cramp and unable to create a break point as he lost 6-4 6-3 6-3.

"There's nothing better than playing in front of the home crowd here in New York," Sock said. "I put it out there on the line on every point."

Sock, 23, will face France's Jo-Wilfried Tsonga, who beat South African Kevin Anderson 6-3 6-4 7-6 (7-4), in the fourth round.