Dan Evans won the longest match in US Open history after staging an incredible comeback in the fifth and final set.

“It was a hell of a match,” he said. “Now I just want to go to bed.”

The British No.5 was suffering from cramp as he fell 0-4 in the decider against No.23 seed Karen Khachenov. But the Davis Cup star then won the final six games to triumph 6-7 7-6 7-6 4-6 6-4 in five hours and 35 minutes.

It was a survival of the fittest in the hot and humid conditions on Court 5 before the Russian put a backhand into the net on the third match point. The previous record was five hours and 26 minutes in the 1992 semi-final between Stefan Edberg and Michael Chang.

The gutsy win brought an end to a terrible run of form. He had lost his previous 10 Tour-level matches stretching back to Miami in March – and had dropped down to world No.184 after playing the Olympics with Andy Murray instead of defending his title in Washington.

Evans, who had to pull out at Queen’s Club after suffering a knee injury, told Sky Sports: “I haven’t played a bunch of tennis this year. I just tried to keep fighting. I thought I was out. I felt a little sorry for myself. And then I was trying to get myself going, and I didn’t want to go out of another Slam with not much fight, and with a whimper.

“I don’t even know how long the match was. I could see he was struggling a bit, and I just tried to just grab a game at a time. My serve was obviously really, really, really bad,. I’ve just got a bad headache now, and just got to get rid of that physically.”

Evans, who had spoken before the final Grand Slam of the year about looking forward to next season, added: “I knew that I hadn’t put the work in because of just being a bit hurt. And obviously, I came out her late as well. I think maybe I got a bit of luck at the end with him hurting and me you obviously feel a bit better when you’re getting on top. And I nearly blew it at the end. But no, I’m really happy. It was a hell of a match. And now I just want to go to bed.”

Evans had failed to take three set points at 5-4 in the first set – and another two in the tiebreak as he lost four consecutive points. And he was slapped with a warning for racquet abuse after dropping his serve in the opening game of the fifth set.

But the Russian then took a medical timeout for treatment on his left thigh and was barely able to move in the closing games. And Evans is now a remarkable 5-0 against the world No.22.