Dan Evans produced a gritty comeback from two sets down to beat Alexei Popyrin in a gruelling match and advance to the US Open fourth round for the first time.

Evans dropped to his haunches in disbelief as his victory was confirmed on a Popyrin double fault.

He will face Daniil Medvedev next.

It is the second time Evans has reached the fourth round at a Grand Slam after his run to the last 16 at the Australian Open in 2017.

He has got there with one of the most determined performances of his career, especially considering that his hard-court swing preparations were disrupted as he recovered from Covid-19.

Both players looked exhausted as the fifth set began but Evans was the stronger on serve and was able to step up at the key moments.

He dominated the eventual tie-break and comforted Popyrin at the net, with the Australian hiding his face in his towel after the final point of the match.

"I'm looking forward to relaxing," Evans said afterwards.

"Coming back from Wimbledon, when I was poor, it was difficult. I could have lost that match pretty easily."

Evans steps up at key moment

Evans has admitted his frustrations with his Grand Slam form this season - he fell in the first round of the Australian and French Opens, before reaching the third round at Wimbledon.

He started the year strongly, winning his first ATP Tour title in January, but has not played many matches since contracting Covid-19 in July.

The match could not have started better for him as he broke Popyrin to love in the opening game, but his 22-year-old opponent capitalised on a dip in Evans' form.

Evans struggled for rhythm in the first two sets, although he was still able to create several break chances, but Popyrin's huge serve and follow-up forehand allowed him to take a two set lead.

The turning point came midway through the third set, Evans breaking for the first time since the opening game with a lobbed winner that drew applause from his opponent.

The Briton fought his way out of a 0-30 hole in his next service game and produced a huge service winner to close out the set.

Supported by his team, who were on their feet after every major point, Evans came through a see-saw fourth set that saw five breaks of serve to force an unlikely decider.

Both players were clearly physically at their limit, with Evans calling for a tablet from the trainer, but they still approached the net and ran around the court with startling ease. Popyrin was given an ovation for a pick-up volley at the net that he somehow manged to flick over for a winner.

Popyrin smashed down an ace to win the first point of the tie-break but Evans dominated it from there on in.

It felt almost cruel that the Australian should lose the match on a double fault, but he left court 17 to a standing ovation, while an exhausted Evans looked on in disbelief.

Evans will face a hugely tough test against 2019 runner-up Medvedev, who has yet to drop a set in New York, but he can take confidence from a very fine third-round win.