NEW YORK (AP) — Japan's Kei Nishikori became the first man from Asia to reach a Grand Slam final, stunning top-ranked Novak Djokovic in four sets at the U.S. Open.

Nishikori won 6-4, 1-6, 7-6 (4), 6-3 in stifling heat Saturday afternoon. He had played five-set marathons in his last two matches totaling more than 8 1/2 hours, yet he looked far fresher than a player known as one of the fittest on tour.

Under coach Michael Chang, the 1989 French Open champ, Nishikori has sharpened his mental game to pull out victories like these.

The midday sun beat down on Arthur Ashe Stadium and a thermometer on court showed the temperature nearing 100 degrees (37 Celsius), not counting the humidity of close to 70 percent.