Stan Wawrinka is the first to acknowledge he hasn’t always been the most consistent player – or the strongest mentally.

That’s why, when he shows his mettle during a match, he likes to point his right index finger to his temple.

That signature gesture got a lot of use in the US Open final when Wawrinka surprisingly managed to wear down Novak Djokovic and beat the defending champion 6-7 (1-7) 6-4 7-5 6-3 for his first US Open title and third grand slam trophy overall.

“He was the better player. He was tougher mentally,” said Djokovic, offering two of the highest compliments a tennis player can receive from the talented and sturdy Serb ranked No.1 in the world.

The 31-year-old Wawrinka is the oldest US Open men’s champion since Ken Rosewall was 35 in 1970, and entered Sunday having spent almost exactly twice as much time on court as Djokovic during the course of the tournament: about 18 hours versus. about nine hours.

“I played quite a lot of tennis these two weeks. I am completely empty,” said No. 3 seed Wawrinka.

By breaking in the final game of the second and third sets, and by saving 14 of 17 break points he faced, Wawrinka already had gained the upper hand by the time Djokovic clutched at his left leg and grimaced after missing a forehand while getting broken early in the fourth.

Djokovic was granted the unusual chance to have a medical timeout at a time other than a changeover.

Wawrinka complained about the six-minute break, and Djokovic looked over and apologised.

Later, Djokovic started limping and received more treatment.

Wawrinka has won only five of his 24 career meetings against Djokovic, but has now beaten the 12-time major champion on the way to each of his own grand slam titles, including in the 2014 Australian Open quarter-finals and 2015 French Open final.

Before this matchup, Djokovic praised Wawrinka as “a big-match player”.

He wasn’t always.

Playing in the shadow of his Swiss countryman Roger Federer, Wawrinka needed until his 35th appearance at a major, at age 28, just to get to the semi-finals for the first time.

But look at Wawrinka now. He has now won 11 tournament finals in a row.

He is 3-0 in grand slam finals, beating the No. 1-ranked player each time.

And he did it by coming back against Djokovic, whose French Open title in June completed a career grand slam and made him only the third man – and first in nearly a half century – to win four consecutive major tournaments.

And think about this.

Wawrinka nearly was gone before the end of the US Open’s first week.

He was one point from losing in the third round against 64th-ranked Dan Evans, but eventually won in five sets.

So Sunday’s victory made Wawrinka the first man to win the US Open after saving a match point since Djokovic in 2011.