New York ? Always so cool, so consistent, so in control of his emotions and his matches, Roger Federer amazingly 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 title 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 shocking 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.

“Maybe I look back and have some regrets about it,” said Federer, never before beaten by anyone other than Rafael Nadal in a major final. “But, you know, you can’t have them all and can’t always play your best.”

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 Nadal the most lopsided loss of his Grand Slam career in the semifinals Sunday, del Potro came back the next day and rattled Federer.

“I would like to congratulate Juan Martin on an unbelievable tournament. I had a great one myself, too,” Federer said, “but he was the best.”

That’s some compliment.

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.”

He also got steamed while up a set and serving at 5-4 in the second. Del Potro tried a forehand passing shot that was called wide, but he challenged, and the replay system showed he was right. Federer kept glancing at the mark the shot left on the blue court, even into the next game, and del Potro wound up stealing the set.

“That one cost me the match, eventually,” Federer said.

Tennis

Serena apologizes

New York — Serena Williams apologized Monday for what she called her “inappropriate outburst” during her semifinal loss to Kim Clijsters at the U.S. Open.

“I want to sincerely apologize FIRST to the lines woman, Kim Clijsters, the USTA and mostly tennis fans everywhere for my inappropriate outburst,” Williams’ latest statement said.

College Football

Hunter doubtful for OSU

Stillwater, Okla. — Starting tailback Kendall Hunter is doubtful for No. 16 Oklahoma State’s game Saturday against Rice due to an injured right leg.

Arnaud still ISU’s starter

Ames, Iowa — Iowa State quarterback Austen Arnaud will start Saturday’s game at Kent State despite being pulled during the third quarter of last weekend’s loss to Iowa.

UCLA undecided on QB

Los Angeles — UCLA coach Rick Neuheisel is expected to announce today whether veteran Kevin Craft or freshman Richard Brehaut will fill in for injured QB Kevin Prince this weekend against Kansas State.

Wisconsin not over flu

Wisconsin’s not quite over the flu. Badgers coach Bret Bielema said Monday at his weekly news conference that after more than 40 guys were sick over the course of last week, two new players showed flulike symptoms on Sunday.

NFL

Bears’ Urlacher done

Lake Forest, Ill. — Bears linebacker Brian Urlacher went on injured reserve after having surgery Monday to repair a dislocated right wrist and will not be back this season, a major blow for a team with high expectations.

McNabb uncertain

Philadelphia — Donovan McNabb once played four quarters on a broken ankle. A cracked rib can’t keep him out.

Can it?

McNabb is not ruling himself out for the Eagles’ game against New Orleans next Sunday.

But he does have a backup: Jeff Garcia, a 10-year veteran who played for Philadelphia in 2006 and went 6-2 in eight starts — including the playoffs — while McNabb was injured, agreed to terms with the Eagles on Monday.

49ers might change offer

Santa Clara, Calif. — Coach Mike Singletary said Monday the San Francisco 49ers have discussed changing their offer to top draft pick Michael Crabtree.

Panthers stick with QB

Charlotte, N.C. — Jake Delhomme is still Carolina’s starter — even after 11 turnovers in two games. He does have a new backup, however, with the arrival of A.J. Feeley to replace the injured Josh McCown.

Jets waive CB Cole

Florham Park, N.J. — The New York Jets have waived cornerback Marquice Cole to make room for the reinstatement of suspended defensive end Shaun Ellis

Seahawks LB out 2 weeks

Renton, Wash. — The Seahawks’ linebacking unit will be without Leroy Hill for at least a couple of weeks. The Seahawks signed D.D. Lewis, who was released at the end of training camp, to help bolster the unit.

Broncos’ LB Larsen out

Englewood, Colo. — Denver Broncos linebacker Spencer Larsen will miss a few weeks after injuring his shoulder in a fall in the locker room at Cincinnati.

Falcons re-sign Haynes

Flowery Branch, Ga. — Verron Haynes has re-signed with the Atlanta Falcons only two days after he was released. Haynes, a running back from the Georgia, was listed as the backup to fullback Ovie Mughelli before he was released Saturday.

Giants duo out 2 weeks

East Rutherford, N.J. — New York Giants first-round draft pick Hakeem Nicks and running back Danny Ware are probably going to be sidelined at least two weeks due to injuries sustained in the season opener.

Bills sign TE Stupar

Orchard Park, N.Y. — The Buffalo Bills have signed tight end Jonathan Stupar to the 53-man roster and released wide receiver Justin Jenkins.

Jaguars lose DE Hayward

Jacksonville, Fla. — Jacksonville Jaguars defensive end Reggie Hayward took a pay cut before the season and signed a new one-year contract filled with incentives. He won’t reach them. Hayward broke his left leg Sunday at Indianapolis and will miss the rest of the season.

Players to donate brains

Boston — Three NFL players announced Monday they will donate their brains and spinal cord tissue to a Boston University medical school program that studies sports brain injuries.

Even though dozens of former NFL players have agreed to donate their brains after death, Baltimore Ravens center Matt Birk, Seattle Seahawks linebacker Lofa Tatupu and Arizona Cardinals receiver Sean Morey are the first active players to do so.

Courts

Teens sue minor team

Trenton, N.J. — Three teenagers who say they were tossed from a New Jersey ballpark over their refusal to stand during the song “God Bless America” are suing the minor-league Newark Bears. The boys argue that their constitutional rights were violated when they were asked to leave Newark’s Bears and Eagles Riverfront Stadium on June 29 by Bears’ president and co-owner Thomas Cetnar.

NBA

Griffin cleared to play

Los Angeles — No. 1 NBA Draft pick Blake Griffin has been cleared to work out with the Los Angeles Clippers after hurting his shoulder during the summer league.