Andy Murray reaches quarterfinals in Monte Carlo

Andy Murray reached the quarterfinals of the Monte Carlo Masters on Thursday after Julien Benneteau injured his ankle and retired near the end of a hard-fought first set with the score at 6-5.

Benneteau, a former French Open quarterfinalist, caused the third-seeded Murray problems throughout a set in which both players were aggressive.

The Frenchman dictated many of the rallies, troubling Murray with some big forehands and driving him back with some stinging backhands.

But Benneteau, scampering to retrieve a shot from the baseline, slipped and rolled his right ankle. He also hurt his right wrist as he tried to break his fall.

After lengthy treatment, Benneteau briefly continued before retiring. Murray next plays sixth-seeded Tomas Berdych of the Czech Republic, who recovered from a shaky first set to beat No. 12 Kei Nishikori of Japan 2-6, 6-2, 6-4.

Nishikori only lost two points on his serve in the first set and broke Berdych twice.

Murray, meanwhile, struggled to hold his opening service game and then broke Benneteau. But the Frenchman broke straight back when Murray, who had saved four break points, hit a forehand wide on the fifth.

On the same center court days ago, Argentine player Juan Monaco also turned his ankle in an almost identical way to Benneteau, and had to pull out of his match against Dutchman Robin Haase.

Benneteau had a lengthy treatment on his ankle, with Murray even jogging over to bring him some ice to place on it.

He got back up to finish the last two points of the 11th game, but Benneteau had to switch to his left hand, and feebly returned Murray's serve wide on one point.

At the changeover, Benneteau took another, shorter, medical time-out on his wrist as Murray jogged on the spot to keep his body warm.

To loud applause, Benneteau rose out of his chair, and prepared to serve. But he realized he would be unable to and shook his head.

Later on Thursday, seven-time defending champion Rafael Nadal was playing qualifier Mikhail Kukushkin of Kazakhstan, while top-ranked Novak Djokovic was to play No. 16 Alexander Dolgopolov of Ukraine.