NEW YORK — Roger Federer was a twitchy, unsettled mess, channeling his inner Serena Williams by lecturing the chair umpire. And this was after he had won the third set.
The crackling forehands of his 20-year-old opponent, Juan Martin del Potro, bothered him. Del Potro's sneaking glances toward his coach before he would ask for a call to be challenged bothered him. The swirling winds, the blowing trash, the noisy crowd -- these were moments of imperfection unappreciated by the tennis maestro.
All these bothers added up until there was Del Potro of Argentina standing in the middle of the court, holding up a trophy, beating the five-time defending champion, 3-6, 7-6 (5), 4-6, 7-6 (4), 6-2, in the finals of the U.S. Open on Monday night at Arthur Ashe Stadium.
After a Federer backhand flew long, on his third championship point, Del Potro dropped to the ground, flat on his back. Looking at the sky, it must have been how Federer had felt all match, trying to solve the game of the 6-foot-6 Del Potro, now the tallest Grand Slam tournament winner.
"I don't have words to explain it," Del Potro said of his victory.
This was the first Open final to go the ultimate five sets since 1999. Del Potro is the first Argentine man since Guillermo Vilas in 1977 to win the U.S. title and Vilas was in the stands Monday standing and cheering for Del Potro.
Federer had won 40 consecutive matches here in ways dominating and imperious, but almost never had he become unsettled the way he did this time.
During the four-hour, six-minute match, Federer was overheard on national television muttering an audible obscenity and engaging chair umpire Jake Garner in a tempestuous argument over how Del Potro was using the challenge system.
"Don't tell me to be quiet, OK?" Federer said to Garner. "When I want to talk, I talk."
At the post-match news conference, Federer reminded reporters where he stood on challenges in the first place.
"You know what I think about Hawk-Eye," he said. "Shouldn't be there in the first place. So then the second question shouldn't happen. It is what it is."
Meanwhile, Del Potro embraced the moments, bad and good. If he missed an easy forehand or served up consecutive double faults to lose the third set, he would pull his shirt over his head or slap himself on the arm. And once when he hit a big winner, Del Potro exchanged high fives with some front-row patrons.
By the fifth set, Del Potro was knocking the 28-year-old Federer to his knees with his monstrous forehand. Federer, the father of baby twin daughters, was made to look clunky when he was forced to block back a Del Potro serve or when he could only turn his head to watch a passing shot from Del Potro skim past his face.
Federer had last lost in this tournament against another Argentine, David Nalbandian. He had been the heavy favorite to become the first man since Bill Tilden in 1925 to win six straight Opens.
Yet, unlike at the Australian Open, when Rafael Nadal had beaten him in five sets, Federer had no tears.
"Today I'm OK with it," Federer said. "I'm tired. I was tired in the other one too. Sometimes they hit you more in other ones."
Oh, and maybe it was the music too. At the end of the Open, the sound system explodes.
"I don't get hit emotionally as bad as maybe in Wimbledon and Australia where it becomes super quiet at the end of the finals and you have a lot of things going through your mind," Federer said.
For Del Potro, the end of the match was one to savor amid the cheers of the crowd. But when the new champion was told by CBS announcer Dick Enberg that there was no time to speak to the crowd in Spanish, he insisted and during those words became teary.
Later in the interview room, Del Potro explained his jumbled emotions.
"When I lay down to the floor, many things come to my mind," Del Potro said. "First my family and my friends and everything. I don't know how I can explain, because it's my dream. My dream done. It's over. I will go home with a trophy and it's my best sensation ever in my life."
It's a feeling Federer understands. He's won 15 of these major tournaments. Just not six Opens in row.
-- (BEGIN TEXT OF INFOBOX) Federer's finals
A look at how Roger Federer has fared in the finals of Grand Slam events in his career:
2004: def. Lleyton Hewitt, 6-0, 7-6 (3), 6-0.
2005: def. Andre Agassi, 6-3, 2-6, 7-6 (1), 6-1.
2006: def. Andy Roddick, 6-2, 4-6, 7-5, 6-1.
2007: def. Novak Djokovic, 7-6 (4), 7-6 (2), 6-4.
2008: def. Andy Murray, 6-2, 7-5, 6-2.
2009: lost to Juan Martin del Potro, 3-6, 7-6 (5),
4-6, 7-6 (4), 6-2.
2003: def. Mark Philippoussis, 7-6 (5), 6-2, 7-6 (3).
2004: def. Roddick, 4-6, 7-5, 7-6 (3), 6-4.
2005: def. Roddick, 6-2, 7-6 (2), 6-4.
2006: def. Rafael Nadal, 6-0, 7-6 (5), 6-7 (2), 6-3.
2007: def. Nadal, 7-6 (7), 4-6, 7-6 (3), 2-6, 6-2.
2008: lost to Nadal, 6-4, 6-4, 6-7 (5), 6-7 (8), 9-7.
2009: def. Roddick, 5-7, 7-6 (6), 7-6 (5), 3-6, 16-14.
2006: lost to Nadal, 1-6, 6-1, 6-4, 7-6 (4).
2007: lost to Nadal, 6-3, 4-6, 6-3, 6-4.
2008: lost to Nadal, 6-1, 6-3, 6-0.
2009: def. Robin Soderling, 6-1, 7-6 (1), 6-4.
2004: def. Marat Safin, 7-6 (3), 6-4, 6-2.
2006: def. Marcos Baghdatis, 5-7, 7-5, 6-0, 6-2.
2007: def. Fernando Gonzalez, 7-6 (2), 6-4, 6-4.
2009: lost to Nadal, 7-5, 3-6, 7-6 (3), 3-6, 6-2.
-- Source: Associated Press