PARIS -- Defending French Open champion Maria Sharapova needed only 54 minutes to advance Monday, beating Hsieh Su-wei 6-2, 6-1 in the first round, while former top-ranked player Caroline Wozniacki ended a five-match losing streak by defeating Laura Robson of Britain 6-3, 6-2.
Sharapova dictated the action, compiling a 25-8 edge in winners, including the backhand she hit to end the match.
A year ago, Sharapova won the championship at Roland Garros to complete a career Grand Slam, adding to her titles from Wimbledon in 2004, the U.S. Open in 2006, and the Australian Open in 2008. She has won 37 of her past 38 first-round matches at major tournaments.
Wozniacki made fewer unforced errors than Robson, breaking the British teenager twice in the first set and three times in the second.
A runner-up at the 2009 U.S. Open, Wozniacki had her best showing at Roland Garros in 2010 when she reached the quarterfinals.
Robson reached the fourth round of the U.S. Open last year, becoming the first British woman since Jo Durie in 1991 to reach that stage of a Grand Slam tournament.
Seeded sixth, Li came into the match 0-3 on clay against Medina Garrigues but raced to a 4-love lead after 20 minutes. Li broke serve six times and came forward aggressively, winning 13 of 16 points at the net.
Li is one of six former champions in the women's draw.
No. 4 Agnieszka Radwanska defeated Shahar Peer 6-1, 6-1. Radwanska, last year's Wimbledon runner-up, played for the first time since withdrawing before last week's Brussels tournament with a recurrence of the right shoulder injury that has bothered her the past couple of years.
"I decided to have a week of rest and just practice," she said. "I think it was a good move."
She'll next play American Mallory Burdette, who won in her Roland Garros debut Sunday. Radwanska was asked what she knew about her second-round opponent.
"To be honest, not much. Nothing at all, actually," she said with a smile. "I might Google her."
The U.S. women fanned out to remote courts and quietly went 6-1. That included victories by Madison Keys, who won her Roland Garros debut, and by Melanie Oudin, who ousted No. 28 Tamira Paszek 6-4, 6-3. No. 17 Sloane Stephens, who reached the fourth round last year, beat Karin Knapp 6-2, 7-5.
"A lot of people say, 'Oh, the Americans, they're not that good on the red clay.' A lot of us want to prove a point this year and do well here," said Oudin.
The search for the next generation of U.S. stars has been ongoing, which made Monday's success notable. Keys beat Misaki Doi 6-3, 6-2; Vania King defeated Alexandra Cadantu 7-6 (3), 6-1; Bethanie Mattek-Sands eliminated Lourdes Dominguez Lino 6-4, 6-1; and No. 29 Varvara Lepchenko beat Mirjana Lucic-Baroni 6-1, 6-2.
"It's funny, because a couple of years ago, everyone was asking me: Where is women's tennis?" Mattek-Sands said. "Here we are now."
Information from The Associated Press was used in this report.