NEW YORK — 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 gesture got a lot of use in the U.S. Open final Sunday, 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 U.S. 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 world No. 1. "He knew what to do. And I was just unlucky in some moments. And that's it." Wawrinka, 31, is the oldest U.S. Open men's champion since Ken Rosewall was 35 in 1970. He entered Sunday having spent almost exactly twice as much time on court as Djokovic during the tournament: about 18 hours versus about nine. "I played quite a lot of tennis these two weeks. I am completely empty," Wawrinka, No. 3, said.By breaking in the final game of the second and third sets, and by saving 14 of 17 break points he faced, Wawrinka 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. He removed both shoes and socks so a trainer could help with toe blisters. Wawrinka complained about the six-minute break, and Djokovic apologized. Later, Djokovic started limping and received more treatment. "We played almost four hours," Djokovic said, "and I think I can speak in the name of Stan, as well: We both felt it."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 Grand Slam titles, including in the 2014 Australian Open quarterfinals and 2015 French Open final. Before this matchup, Djokovic praised Wawrinka as "a big-match player." Wawrinka wasn't always. Playing in the shadow of his more accomplished Swiss countryman and good friend, Roger Federer, Wawrinka needed until his 35th appearance at a major, at age 28, just to get to the semifinals for the first time. Wawrinka now has won 11 tournament finals in a row. He is 3-0 in Grand Slam finals, beating the No. 1 player each time. Take that trio of highest-stakes matches out of the equation and Wawrinka is 0-19 in all other matches against the top man. He won Sunday 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. Wawrinka nearly was gone before the end of the 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 U.S. Open after saving a match point since Djokovic in 2011. "You're a great champion, a great person. Because of you, I am where I am today," Wawrinka said to Djokovic. "We know each other (for) many, many years, and I had the chance to practice many times with him and to play him on a big stage."