Defending champion Ana Ivanovic struggled on the important points in her opening match at the French Open before beating Sara Errani of Italy 7-6 (3), 6-3 today to reach the second round.
The eighth-seeded Serb converted only five of the 20 break points she earned against her opponent. Errani broke three times and even served for the first set at 5-4.
Ivanovic, who beat Dinara Safina in last year's final, pulled out of this month's Madrid Open with a knee injury, and her right knee was taped Sunday at Roland Garros.
Ivanovic finished the match with seven double-faults and six aces, while the 44th-ranked Errani did a good job of moving the defending champion all over the court.
Both players questioned calls on the red clay, but Ivanovic was on the winning side of a crucial challenge in the tiebreaker. At 1-1 with Errani serving, the Italian hit a ball wide that Ivanovic returned. Errani then sent a winner to the other side of the court on her next shot and believed she had taken the lead, but Ivanovic called for the chair umpire, who checked the previous mark and overruled the call.
Errani stood at the net and complained, but the call stood and Ivanovic won the next two points on serve to take a 4-1 lead.
The 21-year-old Ivanovic also reached the final at Roland Garros in 2007, and last year's Australian Open final. She was the world's top-ranked player for 12 weeks in 2008 but has dropped to No. 8.
Also, 25th-seeded Li Na of China defeated Marta Domachowska of Poland 6-4, 6-2 and 27th-seeded Anastasia Pavlyuchenkova of Russia beat Ioana Raluca Olaru of Romania 6-3, 6-2.
In the men's field, third-seeded Andy Murray was scheduled to play Juan Ignacio Chela later Sunday, while Marat Safin and eighth-seeded Fernando Verdasco were also to play.