Sports

Upstart del Potro denies Federer his 6th crown

Juan Martin del Potro didn’t sound like someone who was about to pull off a stunning upset just before he walked onto the court at Arthur Ashe Stadium yesterday for the U.S. Open final.

“I feel a little nervous,” the 20-year-old said just prior to facing five-time defending champion and top-seed Roger Federer. “I have to do everything perfect and have to play much better than yesterday to have chance to win, but it will be tough.”

Five sets and a little over four hours later, he had pulled it off.

With the 3-6, 7-6, 4-6, 7-6, 6-2 victory, the sixth-seeded Argentine became the only player other than Rafael Nadal to defeat Federer in a Grand Slam final.

Federer was up 5-3 in the second set and seemed poised to join Bill Tilden as the only players to win six consecutive U.S. Opens, but he was unable to close out the set and dropped a tiebreak for the first time in an Open final.

“I should never have lost so many chances,” said Federer, who won two five-setters in Grand Slam finals this year. “It was just a pity. I think if I win the second set, I’m in great position to come through. Unfortunately, I didn’t win that and that was it.”

Even though he recovered to win the third set, Federer wasn’t himself. He struggled throughout the match with his serve and detoured from his normal unflappable demeanor when he ripped into chair umpire Jake Garner while up 5-4 in the third.

Federer was unhappy with how long del Potro was given to challenge a point and the result.

When Garner told him he had argued long enough, Federer responded: “Don’t tell me to be quiet, I don’t give a [expletive].”

But Federer insisted that he was not affected by that later in the match.

“I don’t get distracted by that stuff,” said Federer, who had won 40 matches in a row at the Open since David Nalbandian beat him in 2003. The Swiss Maestro had won 33 of his previous 34 Grand Slam matches. And he has made the final at 17 of the past 18 Grand Slam tournaments, 21 overall.

And after he won that third set to go up a set, Federer appeared to have the title within his sights again.

But del Potro fought back one more time, hanging on to win another tiebreak, 7-4 and never looked back, racing to a 3-0 lead in the fifth.

“I had nothing to lose,” del Potro said.

He played like it, using his long frame, strong serve and powerful forehand.

“I tried everything,” Federer said. “It didn’t work.”

So del Potro, who took Federer to five sets in this year’s French Open semis, won his first Grand Slam in his first finals appearance.

“It’s not an easy thing to do,” Federer said. “Especially coming out against someone like me with so much experience.”

Del Potro gained plenty of that in this tournament. He beat Nadal — for the third time this year — in the semis and Federer admitted that this was likely not the last time the new champion would make his presence felt.

“Rafa, we’ve had some epic ones, sure, great ones over the years,” Federer said of their Slam finals battles. “Who knows? Maybe del Potro is gonna join that, as well.”

But for del Potro, it will be hard to top this one.

“Everything is perfect,” del Potro, who is the fifth-youngest U.S. Open champion and the first man from Argentina to win the event since Guillermo Vilas in 1977, said. “I don’t know how I can explain, because it’s my dream. My dream is done. It’s over.”

dan.martin@nypost.com