BEIJING -- Roger Federer directed an angry scream toward his feet. He swatted a stray ball in frustration. He slapped his thigh, hung his head and stomped behind the baseline.
And as a last resort, he questioned calls, something he hates to do. That merely made him madder: He went 0-4 on replay challenges.
For Federer, it was that kind of night. It has been that kind of year.
Federer's bid for his first Olympic singles medal ended Thursday night when he lost to American James Blake. With the sort of lackluster performance once unthinkable for Federer, he was eliminated in the quarterfinals 6-4, 7-6 (2).
Blake's victory was a stunner. He had won only a single set in eight previous matches against Federer.
"If you play him enough times, he's bound to have an off day," Blake said.
But the top-seeded Federer has been battling a yearlong slump that has left him stalled at 12 major titles, two shy of Pete Sampras' record. His Wimbledon reign ended last month, and he came to Beijing knowing he would lose the No. 1 ranking to Rafael Nadal next week after 4½ years on top.
"It was one of the goals of the season for me to do well here," Federer said. "This obviously is a big blow, because I expected more."
Federer said he may have made a mistake this year by playing too much and not practicing enough. But he blamed his latest defeat largely on Blake.
"I've played him on many occasions, but I think this was the best I've seen him," Federer said. "I'm happy for him. He's a good guy. I hope he can go all the way now."
Federer's latest defeat means no rematch in Sunday's final against Nadal, who won in epic fashion when they met for the Wimbledon title.
Nadal beat Jurgen Melzer 6-0, 6-4 in a match that ended at 1:08 a.m. His semifinal opponent will be No. 3 Novak Djokovic, who rallied to reach the semifinals by beating Gael Monfils 4-6, 6-1, 6-4 in a match that ended at 12:50 a.m. Friday.
Blake's semifinal opponent will be No. 12 Fernando Gonzalez of Chile, who defeated Paul-Henri Mathieu of France 6-4, 6-4.
Federer had been seeking his first Olympic medal after losing in the singles semifinals in Sydney and in the second round in Athens. He was scheduled to play a quarterfinal doubles match later Thursday with Swiss partner Stanislas Wawrinka.
The upset was sweet for the No. 8-seeded Blake, a first-time Olympian at 28 and the lone U.S. male to survive the first round of singles.
"I proved that I played with the best tonight, and it couldn't have happened to me on a better stage," Blake said.
Blake said he always believed he could improve his luck
against the 12-time Grand Slam champion.
"I always believed in myself," said Blake, who is now just one
victory away from a guaranteed medal. "I'd lost
to him eight, nine, 10, 50 times, I don't know how many, but I
had the feeling it could be my day today."
Top-seeded Mike and Bob Bryan of the United States advanced to the semifinals in doubles by beating Lleyton Hewitt and Chris Guccione of Australia 6-4, 6-3.
Play began after a rain delay of 3 hours, 35 minutes, with Federer on center court first, and he seemed off his game from the start. His forehand -- once the sport's most feared -- was unreliable, and he repeatedly struggled to hold serve.
Blake earned the first break in the final game of the opening set. On set point, Federer left his feet for a spectacular backhand save that extended the rally, but with his next shot he floated an easy backhand into the net.
His shoulders sagging, he was broken again two games later and fell behind 3-0 in the second set.
Federer finally showed life by breaking back in the fifth game and holding the rest of the way to reach 6-all. But Blake played a flawless tiebreaker, while Federer made two unforced errors and popped up a volley.
When Federer sailed a return long on match point, Blake screamed "Yeah!" Federer ripped off his headband and walked head down to the net.
"In a lot of the other matches, it has been a point here or there," Blake said. "That's why he was No. 1 in the world -- he played those points better than everyone. Today I played them well."
The Associated Press and Reuters contributed to this report.