Wawrinka beats Nishikori to set up final against Djokovic

- The Swiss has lost 19 of 23 matches against defending champion Novak Djokovic, who beat French 10th seed Gael Monfils in his semi-final, but Stan Wawrinka has beaten the Serb on his way to both of his Grand Slam titles.

Stan Wawrinka outslugged Japanese sixth seed Kei Nishikori 4-6, 7-5, 6-4, 6-2 in energy-sapping humidity at Flushing Meadows on Friday to set up a US Open final against world number one Novak Djokovic.

The third-seeded Swiss took a while to get untracked as 2014 US Open runner-up Nishikori played a near flawless opening set of the semi-final with just two errors.

The Japanese broke Wawrinka to start the second set, but the Swiss started rolling after breaking back in the fourth game and Nishikori, who went five tough sets to upset second seed Andy Murray in a four-hour quarter-final, began to wither.

Wawrinka, the 2014 Australian Open winner and 2015 French Open champion, broke Nishikori in the last game of the second, third and fourth sets to reach his first US Open final.

"He was playing really good from the beginning, he was dictating," Wawrinka said. "He was putting pressure on me, didn't give me any time. I had to wait. I had to fight.

"And he also started to get tired a little bit. That's when I started to get aggressive."

The Swiss has lost 19 of 23 matches against defending champion Djokovic, who beat French 10th seed Gael Monfils in his semi-final, but Wawrinka has beaten the Serb on his way to both of his Grand Slam titles.

"To tell myself I'm going to be in the final is something crazy," he said.

"I'm really excited. I watched the final so many times here. Roger (Federer), Novak, Rafa (Nadal) they are amazing champions. To play Novak in the final... is going to be something special."

Djokovic, a 6-3 6-2 3-6 6-2 winner against Monfils, is prepared for a sterner test from Wawrinka.

"Stan is a big match player," Djokovic said when asked about the Swiss, who has won his last 10 finals.

The hard-working Wawrinka stayed on track by coming up big on key points, saving 11 of 15 break points held by the talented Japanese at the Arthur Ashe Stadium.

Wawrinka saved four break points in the seventh game of the second set to stay on serve at 4-3 and saved two more in the ninth game before levelling the match.

Nishikori, who looked fatigued, fell behind 3-1 in the third set but rallied to bring it back on serve at 4-3 and appeared to gain a respite when rain forced a delay to shut the roof.

Once again, Wawrinka clinched the set on Nishikori's serve when the Japanese lunged to hit a forehand volley on a rifled passing shot and sent it long.

Nishikori, whose 2014 New York campaign made him the first player from an Asian country to reach a Grand Slam final, where he fell to Marin Cilic, lost serve three times in the final set to end the three hour, seven-minute match.

"I was definitely a little bit tired, especially in the end," the 26-year-old Nishikori told reporters. "I think also he was stepping up a little more from the second set.

"It's not easy after playing Andy five sets."