Holder Ana Ivanovic was made to sweat much more than expected in a 7-6, 6-3 victory over unheralded Sara Errani of Italy to reach the second round, in Paris, on Sunday.

"I expected a tough match. I knew I would have to work hard for my points today, and I'm very happy I did that," Ivanovic said.

Marat Safin made sure there would be at least one more date on his French Open farewell tour when he eased past French wildcard Alexandre Sidorenko 6-4, 6-4, 6-4.

Former world number one Safin, playing at Roland Garros for the last time before retiring at the end of the year, will next face France's Josselin Ouanna.

"Hopefully it was not the last time. Maybe I have a couple of more matches here. So it would be great. But I didn't think so deep," he said.

Amelie Mauresmo's French Open dreams turned to dust in the first round on Sunday when she was beaten 6-4, 6-3 by Germany's Anna-Lena Groenefeld.

Mauresmo suffered her earliest defeat since 2001 and with her 30th birthday fast approaching, she is unlikely to have many more chances of improving on her two quarter-final showings here.

Asked if she had again cracked under pressure at Roland Garros, Mauresmo said: "Don't know. I don't know. I don't know."

Lleyton Hewitt had to duck and dive for almost four hours as he saw 55 aces whizz by him on Sunday but still found a way to trip up lofty Croatian Ivo Karlovic 6-7, 6-7, 7-6, 6-4, 6-3 in the first round of the French Open.

The former world number one celebrated his moment of triumph by saluting the crowd with a clenched fist.

Despite winning more than eight games on aces alone, Karlovic was four thunderbolt serves shy of equalling the all-time record of American Ed Kauder, who fired 59 in 1955.

"His first serve is extremely tough on any surface to get," said Hewitt, who could face a third-round showdown with four-times champion Rafael Nadal.

World number three Andy Murray started his French Open campaign with a 6-2 6-2 6-1 demolition of Argentine Juan Ignacio Chela to book a second round ticket on Sunday.

The Briton, chasing his first grand slam title, will next face either Germany's Mischa Zverev or Italian Potito Starace.

"I wasn't expecting to play that well on the first match. I hit a lot of winners," Murray, who has never won a title on clay, said.