PARIS — Novak Djokovic survived a rough start to his quest for a second straight Grand Slam title today, holding off Denis Gremelmayr 4-6, 6-3, 7-5, 6-2 in the first round of the French Open.

The Australian Open champion was broken in his first two service games on center court and trailed 5-1 in the first set before finding some of his game in the second.

"I wasn't underestimating my opponent, even though it looked like that in the first set," said Djokovic, who reached the semifinals at Roland Garros last year. "He played a couple of semifinals in good tournaments, and he played some three sets with Roger Federer, so I knew that he's a tough player to play against on this surface."

In the third set, Djokovic started to show his frustration, throwing his racket into the red clay after Gremelmayr hit a forehand winner in the opening game.

"This was one of the days when you just can't put your game in the direction that you want it to be," Djokovic said.

No. 6 David Nalbandian and No. 7 James Blake also won. Blake's 6-4, 6-1, 7-6 (3) victory over Rainer Schuettler made him the first American man to reach the second round at Roland Garros since 2006.

In the women's draw, two-time Grand Slam runner-up Ana Ivanovic also struggled before advancing on the opening day of the French Open by beating Sofia Arvidsson 6-2, 7-5.

The first seeded player to lose was No. 15 Nicole Vaidisova. She reached the French Open semifinals in 2006 and the quarterfinals last year, but was upset by Iveta Benesova 7-6 (2), 6-1.

Djokovic took a 4-1 lead after breaking his German opponent in the third set. Trailing 30-15 in the fifth game, the pair traded 28 shots before Djokovic won the point with a smash near the net. The third-seeded Serb then raised his arms over his head and leaned over the net to applause while Gremelmayr looked on smiling.

But after Djokovic held to take a 5-1 lead, Gremelmayr won four straight games to tie it a 5-5.

"He was serving much stronger in the second and fourth sets," Gremelmayr said.

Djokovic is trying to become the first man since Jim Courier in 1992 to win the Australian and French Opens in the same year.

"It's good to hear that the people are talking about more than two (players)," Djokovic said, referring to Federer and three-time defending champion Rafael Nadal.

At last year's French Open, American men went 0-9 in the first round, with Blake losing to Ivo Karlovic.

"We all feel like, you know, last year was an aberration that should never happen again," Blake said, "and this year we're definitely looking for better results."

Blake is 9-6 on clay this year, but he struggled to finally beat Schuettler, who has lost in the first round at Roland Garros in seven of his nine appearances.

Blake won the first set on the first break of serve in the match, and then raced out to a 5-0 lead in the second set. In the third, Blake led 5-1 but his German opponent won five straight games to go ahead 6-5.

The second-ranked Ivanovic, who became the first player representing Serbia to play in a major final at last year's French Open, had six double-faults on center court and was broken by her Swedish opponent when serving for the first set at 5-1.

"I let my intensity go down for a bit ... and she used it and she started playing much better," Ivanovic said. "But towards the end I'm happy that I found back my game and managed to break her back, and win the second set."

Ivanovic, who reached the final at this year's Australian Open, was also broken in the third game of the second set. In her next service game, while trailing 3-1, Ivanovic saved three break points before holding. Then, after breaking Arvidsson to get to 3-3, the Serb saved two more break points.

Ivanovic also beat Arvidsson in the first round at Roland Garros last year, winning 6-2, 6-0 on her way to the final, where she lost to Justine Henin. The Belgian is not defending her title, having announced her retirement this month.

"Last year I just broke into top 10, and I had much less pressure, honestly speaking," Ivanovic said. "Now I'm No. 2, and obviously I have more expectations for myself. So that's something I'm still learning how to deal with it."

Ivanovic will face Lucie Safarova in the second round. The Czech player beat Sandra Kloesel of Germany 6-1, 6-1.

Vaidisova reached the fourth round at the Australian Open, but she has now lost six straight matches.

"It's always hard to play your best friend," the 19-year-old Vaidisova said.

Nalbandian, a two-time French Open semifinalist, advanced to the second round by beating Carlos Berlocq of Argentina 6-2, 6-4, 6-1.

Later Sunday, eight-time Grand Slam champion Serena Williams was to face Ashley Harkleroad and former champions Gustavo Kuerten and Carlos Moya were playing.