PARIS -- Chasing a shot, Roger Federer caught his right shoe in the French Open's red clay, twisting that foot awkwardly and tumbling to the ground.
Soon enough, he was in a real rut, in danger of his earliest exit from a Grand Slam tournament in nine years.
Federer regrouped and restored order eventually, coming back from a two-sets-to-one deficit to beat 15th-seeded Gilles Simon of France 6-1, 4-6, 2-6, 6-2, 6-3 on Sunday in the fourth round to reach his 36th consecutive major quarter-final.
"I didn't hurt myself or anything," Federer said afterward. "But maybe I did lose that touch of confidence."
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.
But Simon, a former member of the top 10, could not keep Federer down. Still, Federer acknowledged the need to "tidy up my play," before he faces another Frenchman, No. 6-seeded Jo-Wilfried Tsonga, in the quarter-finals.
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 matches in a row after dropping the first two sets of each.
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. Not only did Robredo trail two sets to none, but he also was behind 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.
"I don't know what adjective to use," he said.
Robredo's first French Open quarterfinal since 2009 -- he missed the tournament in 2011 and 2012 because of left leg problems that required surgery -- will be against another Spaniard, No. 4 David Ferrer, who eliminated No. 23 Kevin Anderson of South Africa 6-3, 6-1, 6-1.
Tsonga, the 2008 Australian Open runner-up, had little trouble getting past Viktor Troicki of Serbia 6-3, 6-3, 6-3. Tsonga is 3-9 for his career against Federer, but he did come back from a two-set hole to win their 2011 Wimbledon quarterfinal.
It was Federer who had to change the direction of things Sunday against Simon.
Did it pretty quickly, too, exhorting himself more than usual with fist-shaking and yells of "Come on!"
From 2-2 in the fourth set, Federer won seven consecutive games, taking that set and a 3-0 lead in the fifth. That was pretty much that, although the final game sure was tense. Simon held two break points that would have allowed him to get back on serve at 5-4, but Federer erased one with a service winner, the other with a big serve that set up a putaway.
After missing a forehand on his first match point, Federer converted the second when Simon pushed a backhand wide on a 10-stroke exchange.
Federer held his racket over his head in triumph, then swatted a ball into the upper deck. When they met at the net, Simon extended his hand for a shake -- and Federer pulled him in for an embrace.
The victory was Federer's 58th in his French Open career, against 13 losses, equaling the mark for most tournament wins held by Guillermo Vilas and Nicola Pietrangeli. It also was Federer's 900th career win anywhere, which puts him fourth in men's tour history, behind only Jimmy Connors, Ivan Lendl and Vilas.
This one must rank among the toughest.
It came in the same stadium where Federer's streak of 23 Grand Slam semifinals in a row ended with a loss in the 2010 French Open quarterfinals to Robin Soderling (who happens to be the only man to beat Rafael Nadal at Roland Garros).
Federer's major quarterfinal run, a record in the 45-year Open era, began at Wimbledon in 2004, shortly after he lost in the third round of the French Open to three-time titlist Gustavo Kuerten.
"I'm very proud of it. When I retired, maybe it's something I'll look back on and realize that it wasn't easy to do," Federer said, "because it required many sacrifices and winning matches like this one."
-- The Associated Press