The 184th-ranked Evans, once the British No 1, beat world No 22 Khachanov in 5:32 minutes, exceeding the previous record of 5:26 minutes, when Sweden’s Stefan Edberg beat American Michael Chang in the 1992 semi-final.

Court 6 rarely draws much of a crowd at the sprawling Billie Jean King National Tennis Center but droves of fans had assembled by the time the match crossed the five-hour mark, overwhelming the stands despite the sweltering conditions.

It looked as though Khachanov had the Briton on the ropes when he went 4-0 up in the final set, but Evans found a bit of fight left in him to fend off four break points in the fifth game before converting a break point chance in the sixth.

Fans jumped to their feet as Evans fended off another break point in the seventh game and broke into thunderous applause as Khachanov dropped his serve in the eighth.

The Russian shouted with frustration as he let another break point chance slip through his fingers in the ninth but refused to go down without a fight as he saved two match points in the final game.

Evans braced himself on the net in apparent exhaustion briefly after sending over an unreturnable forehand to win it, setting up a meeting with Argentine Mariano Navone.