Kei Nishikori has become the first Japanese man in 81 years to reach a Grand Slam semi-final after seeing off Stanislas Wawrinka at the US Open in a thriller that went the distance.

The 24-year-old prevailed 3-6 7-5 7-6 6-7 6-4, with two sets going to a tie-break, to set up a last-four clash with either Andy Murray or Novak Djokovic.

Wawrinka started brightly, breaking at the first time of asking in the opening set and going on to hold steady against increasing resistance from his opponent to clinch it convincingly.

Nishikori got into his stride in the second set, and the two competitors looked evenly matched, with the Swiss needing to hold with the score at 6-5 to force a tie-break.

His his nerves got the better of him and a double fault at the death levelled the match at one set each.

Although the Japanese broke his opponent's serve in the third set to move 4-2 ahead, his serve faltered shortly after and it went to a tie-break, which Nishikori made hard work of but eventually sealed 9-7 following an epic 18-shot rally.

Set four proved to be the least entertaining, with neither player troubled on serve, forcing the second tie-break of the evening, which Wawrinka wrapped up 7-5 to set up a decider.

The final set was equally close, remaining on serve until the Swiss needed a hold to force yet another tie-break, but a late double fault from him proved decisive, handing Nishikori two match points.

Wawrinka saved one of them but returned a viscous forehand from Nishikori into the net to hand his opponent victory and a place in the semi-finals.