Second seed Maria Sharapova swept past China's Peng Shuai 6-2, 6-1 to reach the fourth round of French Open on Saturday.

The Russian girl fired 27 winners to complete the match in 66 minutes, continuing her chase for the Grand Slam title that still eluded her.

In the final 16, she will next face Czech veteran Klara Zakopalova who put out Russian 22nd seed Anastasia Pavlyuchenkova 6-3, 7-5.

"I came in knowing that I was facing a tough opponent who has beaten me before and against who I have played three sets," said Sharapova.

"She can really play, hits the ball really well, so I tried to keep her moving, tried to get her on the run, and I thought that was really important, especially against her," she said.

Peng, who had her left hand and right leg injured prior to the French Open, said she was tormented during the match.

"Due to the injuries I am suffering, everybody knows that I had no chance to win, and if it had not been the French Open, I would have pulled out," she said.

"And in the match when she felt uncomfortable, she just attacked my backhand where I could not return the ball well and strong, then she could dictate with powerful drives, either straight or cross-court. I felt very helpless and tormented there," she said.

Peng's Davis Cup teammate and the defending champion Li Na battled back to defeat America's Christina McHale 3-6, 6-2, 6-1.

The seventh seed had to draw upon her experience to prevail from a first-set loss.

"In the first set I was made to follow her rythm, feeling as if she is the champion on the court," the 30-year-old said.

"I made some changes in the last two sets and played my game. And I think she lost mainly because she lacks experience, give her one or two years, she could be very formidable," she said.

McHale, ten years younger than Li, agreed that the Chinese veteran's experience made the difference.

"I think her experience did help her get out and be able to raise her level in the second and third," she said.

Italian 14th seed Francesca Schiavone, the 2010 champion and runner-up to Li last year, lost 3-6, 6-3, 8-6 to America's Varvara Lepchenko, the world number 63, who has reached the last 16 of a Grand Slam for the first time.

Wimbledon champion Kvitova, 22, reached the last 16 for the third time but she did it the hard way, serving up eight double faults and committing 37 unforced errors in her 6-2, 4-6, 6-1 win over Russian world number 109 Nina Bratchikova.

Also making the last 16 was Yaroslava Shvedova, a quarter-finalist in 2010, who eased past Spain's Carla Suarez-Navarro 6-4, 7-5.