"I didn't hurt myself or anything," Federer said. "But maybe I did lose that touch of confidence for a little bit, and then I was out of the match there for a bit."
During a rare stretch of mid-match mediocrity from the owner of a record 17 Grand Slam championships the 2009 French Open trophy is part of his collection Federer lost 10 of 13 games, including the one in which he fell.
"I didn't give him time," said Simon, a one-time Grand Slam quarterfinalist. "I managed to start moving him around a bit."
Federer's turnaround was not the biggest of the day. Not even close. That distinction belonged to 32nd-seeded Tommy Robredo of Spain, who is specializing in comebacks: He is the first man in 86 years to win three Grand Slam matches in a row after dropping the first two sets (France's Henri Cochet pulled that off at Wimbledon in 1927).
Robredo did it in the second round Wednesday. He did it in the third round Friday. And then he did it in the fourth round Sunday, defeating No. 11 Nicolas Almagro 6-7 (5), 3-6, 6-4, 6-4, 6-4. Robredo trailed 4-1 in the third set, 4-2 in the fourth and 2-0 in the fifth.
"Nobody dreams of doing such things," said Robredo, who dropped to his knees, leaned forward and wept after winning.
And what about the woman who is everyone's pick to win the title, No. 1 Serena Williams? The 15-time major champion has been nearly flawless, losing a total of 10 games through four matches. She beat No. 15 Roberta Vinci 6-1, 6-3 to extend her winning streak to 28 and set up a quarterfinal against Svetlana Kuznetsova, the 2009 champion who is unseeded this year and defeated No. 8 Angelique Kerber 6-4, 4-6, 6-3.