Stan Wawrinka reacts by pointing to his head after winning...

Stan Wawrinka reacts by pointing to his head after winning the third set against Novak Djokovic in the men's finals at Arthur Ashe Stadium at the 2016 U.S. Open Tennis Championships at the Billie Jean King National Tennis Center in Flushing on Sunday, Sept. 11, 2016. Credit: Newsday / J. Conrad Williams Jr.

A man who sees windows where there seem to be only walls, Stan Wawrinka kept slipping through the smallest openings until he eventually knocked down defending champion Novak Djokovic in a high-energy, high-anxiety, four-hour U.S. Open final last night.

The score was 6-7 (1), 6-4, 7-5, 6-3. The match was a working man’s treasure, an entertainment gem that had the capacity Arthur Ashe Stadium crowd howling throughout.

If they had been lumberjacks, the relentless cuts that Wawrinka and Djokovic took at each other would have cleared a forest. If they had been sword fighters, the thrusts and parries would have left blood all over the stadium floor.

Djokovic took a quick 4-1 lead, a false omen. Wawrinka powered his way back to the tiebreaker and, when he lost that decisively, it was another misleading harbinger. Because, while Djokovic never had lost a match at the Open after winning the first set — he was an astounding 51-0 — he nevertheless had been beaten by twice by Wawrinka after winning the first set in Slam events, at the 2014 Australian and 2015 French.

Sure enough, with a quick service break in the second set’s fourth game, Wawrinka never again allowed Djokovic any breathing room. Djokovic’s clean ground strokes and rubbery athleticism were offset by Wawrinka’s crisp backhand and the ability to play offense from far behind the baseline.

“I don’t know what’s happening right now,” Wawrinka said. “I’m completely empty. I had to bring everything out today against Novak. There was so much emotion, with the crowd, with the atmosphere.”

The irony was that Djokovic, who spent half the time on court that Wawrinka had through the tournament’s first six rounds, was the one who broke down physically at the end. A right toe injury, apparently suffered in the second game of the fourth set, had Djokovic limping between points and twice summoning a trainer between games.

In arriving at the title match, Djokovic had won three matches when two opponents retired and a third never started.

Wawrinka, meanwhile, had needed nine more hours and 10 more sets to work his way through the draw. He also needed a forehand volley winner against a British outsider named Daniel Evans to save a match point in the third round.

But persistence is Wawrinka’s career story, as well as it was last night’s narrative. Never as far as a major-tournament semifinal in his first 35 Grand Slam events, he has advanced at least as far as the semis six times in his last 13 Slams. And his three trips to the final — at the 2014 Australian Open, the 2015 French and last night — all resulted in titles.

“This is amazing,” Wawrinka said. “I came here not expecting to win it, but every time I stepped on the court, I expected to win the match.

“I never had the goal to be Grand Slam champion or to be No. 1, but to be the best that I can. I’m really happy.”

At 31 years and five months, Wawrinka became the oldest U.S. Open male champion since 35-year-old Ken Rosewall in 1970. Pete Sampras was four months younger than Wawrinka is now when he won in 2002.

So suddenly Wawrinka, long in the shadow of Swiss countryman Roger Federer, now has as many major-tournament trophies as Andy Murray, who is considered one of the so-called Big Four of Federer, Rafael Nadal and Djokovic, who have won 42 of the last 47 Slams.

In that time, Murray and Wawrinka are the only other players with three titles. (Juan Martin del Potro and Marin Cilic won the other two.)

Another wall knocked down by the dogged Wawrinka.

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