PARIS — Maria Sharapova struggled again in her Grand Slam tournament comeback at the French Open, needing three sets and a few extra games to reach the third round with a 6-2, 1-6, 8-6 victory over Nadia Petrova today.

Playing with tape on her troublesome right shoulder, the unseeded Sharapova hung on to join top-seeded Dinara Safina and defending champion Ana Ivanovic in the next round.

"Obviously I am spending a little bit more time out there than I want to, but I think I'm learning so many new things, as well," Sharapova said. "I think this was a great match where I had to fight my way through many, many challenges. And I did."

On the men's side, four-time defending champion Rafael Nadal and third-seeded Andy Murray advanced to the third round.

Nadal, attempting to become the first to win five straight French Open titles, extended his French Open record to 30-0 by beating Teimuraz Gabashvili of Russia 6-1, 6-4, 6-2.

"So what?" Nadal said of his accomplishment. "(I'm) happy for the record, but in the end happy for the result."

Murray defeated Potito Starace of Italy 6-3, 2-6, 7-5, 6-4.

Sharapova, a three-time Grand Slam champion who has slipped to No. 102 in the rankings because of her injury layoff, won five straight games to close out the first set.

Trailing 4-2 in the deciding set, she broke the 11th-seeded Petrova to get back on serve at 4-4, and then saved two break points to take a 5-4 lead. She saved another break point while serving at 6-6.

"I got off to a really good start," Sharapova said. "I kind of started stumbling away. Things went in the wrong direction. I was just glad I could pick myself up and keep fighting and do the right things, and end the match with a win."

Sharapova is making her first Grand Slam appearance in almost a year after missing both the U.S. Open and the Australian Open because of her shoulder injury. She had surgery in October.

Safina easily beat 18-year-old Russian qualifier Vitalia Diatchenko 6-1, 6-1, and Ivanovic defeated Tamarine Tanasugarn of Thailand 6-1, 6-2.

Safina took a 5-0 lead to open the match, stretching her streak to 17 straight games after winning 6-0, 6-0 in the first round.

"Pretty good start for the tournament," said Safina, who lost in the Australian Open final and was the runner-up at Roland Garros last year. "I just played a good game today, good enough to win."

Ivanovic looked more comfortable on court after struggling in her opening match. The eighth-seeded Ivanovic broke the 32-year-old Tanasugarn twice in the first set and three times in the second.

"I just want to sort of get my way through the rounds and just feel more comfortable match after match," Ivanovic said. "Today I think I served some aces, which gave me some confidence in my serve, and that's something I've been working on."

The 21-year-old Serb finished with three aces.

No. 9 Victoria Azarenka of Belarus also made it through, while No. 21 Alize Cornet of France reached the second round. No. 15 Zheng Jie of China lost.

The top-seeded Nadal has never lost at Roland Garros, and his 30th straight win on the tournament's red clay gives him the record for most consecutive wins.

Nadal was forced to save three break points in the first game of the match. He only had to save one more the rest of the way, winning in straight sets for the second match in a row.

Murray trailed 5-1 in the third set but broke Starace three straight times to win.

"On clay, there's always time for you to get sort of back into the match and find your game, even if you're struggling," Murray said.

Murray also reached the third round at Roland Garros last year but lost to Nicolas Almagro in four sets. In his only other appearance at the French Open, in 2006, he lost in the first round.

No. 7 Gilles Simon of France, No. 8 Fernando Verdasco of Spain, No. 12 Fernando Gonzalez of Chile and No. 13 Marin Cilic of Croatia also advanced, but French veteran Fabrice Santoro played his last match at Roland Garros.

Santoro, who has made a record 67 Grand Slam appearances, lost in the first round of this year's French Open — his record-tying 20th — to Christophe Rochus of Belgium 6-3, 6-1, 3-6, 6-4.

"Twenty years. That counts for something in a lifetime," Santoro said. "It has been a long road, a fantastic career. I had a lot of fun and learned a lot."

Santoro and Rochus started their match Tuesday, but it was suspended by darkness with the Belgian leading 5-3 in the fourth set. The pair came back out onto the court after Safina's win and played only eight minutes.

No. 21 Dmitry Tursunov of Russia and No. 28 Feliciano Lopez of Spain also lost.