Sharapova has twice reached the quarter-finals at Roland Garros

Second seed Sharapova took just over an hour to crush American Jill Craybas 6-2 6-1 and now meets fellow Russian Alla Kudryavtseva - a French Open debutante.

Williams, the Australian Open champion, was held up longer by Milagros Sequera.

The eighth seed rattled through the first set but then had to recover from 0-3 down to the Venezuelan in the second before prevailing 6-0 7-6 (7-3).

"I pretty much went crazy," said Williams.

"I honestly did not feel my game at all. Even in the first set, I felt like I was not playing well.

"I was struggling to get rhythm - maybe I had too many days off. But I was able to come back and I found more rhythm towards the end."

This gives me confidence but also shows me what I have to improve - I need to be more aggressive Amelie Mauresmo

Sharapova admitted she is still bothered by the right shoulder injury which kept her off court for nearly two months.

"The pain is still there at times," said the 20-year-old.

"For one week I couldn't do anything. I couldn't really move my shoulder up and down because of the pain."

Craybas said she noticed a problem, saying: "She was pretty much doing second serves all the time."

Amelie Mauresmo scrambled into the third round with a 6-3 6-7 (7-3) 6-1 win over fellow Frenchwoman Nathalie Dechy.

Mauresmo was 4-1 down in the second set before recovering to force a tiebreak - which was held up by a rain delay.

Dechy held her nerve and snatched it 7-3 but fifth seed Mauresmo rediscovered her form in the decider.

"I was very tense, very nervous at first", said Mauresmo. "The rain break helped me - I was able to pick my game up in the third set.

"This gives me confidence but also shows me what I have to improve. I need to be more aggressive."

Seventh seed Ana Ivanovic was also in a hurry to reach the third round on Thursday, beating Sania Mirza 6-1 6-4.

Serbian Ivanovic goes on to meet unheralded Romanian Ioana Raluca Olaru, a qualifier playing in her first Grand Slam tournament.

Third seed Svetlana Kuznetsova came back from 5-0 down in the first set to beat Meghann Shaughnessy 7-6 (7-4) 6-3.

Raluca Olaru thrashed Belarussian Tatiana Poutchek 6-3 6-0.