NEW YORK - Normally so cool, so consistent, so in control of his emotions and his matches, Roger Federer let the U.S. Open championship slip from his grasp.
Two points from victory against inexperienced, unheralded Juan Martin del Potro of Argentina, two points from a sixth consecutive title at Flushing Meadows and a record-extending 16th Grand Slam overall, Federer, quite simply, fell apart Monday.
He railed at the chair umpire. His legs grew weary. His double-faults mounted. He could not figure out a way to stop the 6-foot-6 del Potro from pounding forehand after forehand past him. In a result as surprising for who lost as how it happened, the sixth-seeded del Potro came back to win his first Grand Slam title by upsetting the No. 1-seeded Federer 3-6, 7-6 (5), 4-6, 7-6 (4), 6-2.
"Can't have them all," Federer said.
He had won 40 consecutive matches at Flushing Meadows. He 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.
Del Potro? This was the 20-year-old's first Grand Slam final, and he was 0-6 against Federer until now. But after handing Rafael Nadal the most lopsided loss of his Grand Slam career in the semifinals Sunday, del Potro came back the next day and rattled Federer.
Until Monday, Federer was 2-5 in Grand Slam finals against his nemesis, Nadal, and 13-0 against everyone else. Somehow, del Potro never seemed intimidated by the setting or the man many consider the greatest tennis player in history.
The usually unflappable Federer argued with chair umpire Jake Garner during a changeover, using a profanity and saying, "Don't tell me to be quiet, OK? When I want to talk, I talk."
Del Potro, meanwhile, managed to have the time of his young life, high-fiving front-row fans after winning one point, and revelling in the soccer-style serenades of "Ole!" ringing through the stadium.
The four-hour, six-minute match was the first U.S. Open final to go five sets since 1999, and there were no early signs to indicate it would be this competitive - much less end with del Potro down on his back, chest heaving, tears welling, a Grand Slam trophy soon to be in his arms. He is the first man from Argentina to win the U.S. Open since Guillermo Vilas in 1977.
Vilas was in the stands Monday, sitting one row behind Jack Nicklaus.
One simple indication of the difference in age and status of the two finalists: The 28-year-old Federer's guest box was full, with pals such as rock-star couple Gwen Stefani and Gavin Rossdale and Vogue editor Anna Wintour seated alongside Federer's parents, wife and agent. Only three of the 15 available seats were occupied in del Potro's box.
Federer took a 3-0 lead in 15 minutes, winning one point by racing about five feet wide of the doubles alley for a defensive backhand, then sprinting the other way for a cross-court forehand passing winner that he celebrated by yelling and shaking his fists.
He even took time to watch a replay on a stadium video screen. Not quite the "Did he really just do that?!" sort of trick shot Federer pulled against Novak Djokovic in the semifinals - a back-to-the-net, between-the-legs, cross-court passing winner to get to match point - but pretty spectacular, nonetheless.
But del Potro eventually got going, swinging more freely and taking full advantage of Federer's serving woes: 11 double-faults and a first-serve percentage of only 50.
Used to travelling without a full-time coach, Federer generally is quite adept at making mid-match adjustments and dealing with opponents' switches in strategy. But it was del Potro who realized he needed to put full belief in the strength of his 100 mph forehands and not worry about too much else.
That tactic worked, and Federer never found a way to counter it, losing leads in the second set and the fourth set. He was up 5-4 in the fourth, and at 15-30 on del Potro's serve, Federer needed only two more points to become the first man since Bill Tilden in 1920-25 to win the American Grand Slam tournament six years in a row.
Del Potro held steady there, and Federer would never come that close again.