Fabio Fognini pulls out with injured leg

PARIS -- Novak Djokovic had a successful day off from tennis Monday, reaching the semifinals of the French Open when his quarterfinal opponent withdrew because of injury.

Fabio Fognini, who injured a muscle in his left leg while beating Albert Montanes on Sunday, announced Monday that he would not be able to play Djokovic, who is 41-0 in 2011 and has won 43 straight matches overall.

"The doctors say if I play tomorrow maybe it can be dangerous," Fognini said, calling his decision "difficult" and adding he had his leg checked by a doctor only 20 minutes earlier.

Djokovic will not be credited with a victory over Fognini because the Italian withdrew.

That means Djokovic would have to wait until after the French Open -- assuming he won it -- before getting the chance to equal Guillermo Vilas' overall Open era record of 46 straight victories.

Fognini beat Montanes 4-6, 6-4, 3-6, 6-3, 11-9 to reach his first Grand Slam quarterfinal.

While Djokovic relaxed and readied for the semifinals, Rafael Nadal and Juan Ignacio Chela both reached the semifinals with victories on Monday. Nadal beat Ivan Ljubicic 7-5, 6-3, 6-3, while Chela downed Alejandro Falla of Colombia 4-6, 6-2, 1-6, 7-6 (5), 6-2.

While trailing late Sunday, Fognini winced in pain at the baseline after hitting a serve and clutched at his left leg. He had his leg massaged and resumed, but eventually had his troublesome thigh wrapped in a bandage.

"(The match) was really incredible, it was really long. At the end I was not really good," Fognini said. "But I did some examinations after the match. I was crying after the match, also for the pain, but I think that's normal."

While trailing 7-6 and serving at 15-30 -- meaning Montanes was two points from victory -- Fognini hurt his leg.

He called for the trainer and sat down in his changeover chair for a massage while play was halted. When action resumed, Fognini won three points in a row to hold serve for 7-all.

The match lasted 4 hours, 22 minutes.

"I never think to retire," Fognini said.

The 24-year-old Fognini was Italy's first man to reach the French Open quarterfinals since 1995, and first to make it this far at any major tournament since 1998.

"I'm not really happy right now," Fognini said. "It's the best tournament of my career."

Djokovic's next match could be against 16-time Grand Slam champion Roger Federer.

"Walkover from Fognini. Bad luck for him, hope he recovers fast. Today i get to enjoy Paris in a different way :-)" Djokovic wrote on Twitter.

If Djokovic wins his semifinal match, he would equal John McEnroe's Open era record for the best start to a tennis season and clinch the No. 1 ranking.

With three more wins, the second-seeded Serb will match the record of 46 straight wins set by Guillermo Vilas.

The two-time Australian Open champion has never won the title at Roland Garros, but he beat Nadal in two clay-court finals leading up to the French Open.

Federer will have to beat either No. 7 David Ferrer or No. 9 Gael Monfils to advance to the semifinals.