Updated

World No. 1 Victoria Azarenka and defending champion Li Na posted first-round victories at the French Open on Monday.

Azarenka had to rally her way past Italy's Alberta Brianti by a 6-7 (6-8), 6-4, 6-2 score at the world's lone clay-court Grand Slam event.

"Sometimes I felt it was not my day. Sometimes I thought, 'Yeah, maybe I still fight, I still have a chance,"' Azarenka said. "Sometimes it was like, you know what? Forget it. I don't want to do it."

A sloppy Azarenka piled up 60 unforced errors.

"I think it says it all. Bad days happen," Azarenka said. "Unfortunately today I had way more mistakes than I usually do, but, you know, it happens sometimes."

The 22-year-old Azarenka, who won her first major title at the Australian Open back in January, improved to 36-3 this season. She will face little- known German Dinah Pfizenmaier in the second round.

Li handled Sorana Cirstea of Romania 6-2, 6-1 to advance.

The seventh-seeded Li, of China, became the first-ever Asian Grand Slam winner, male or female, by besting then-reigning champion Francesca Schiavone in last year's French Open finale. Schiavone became the first-ever Italian woman to capture a major title by beating Aussie Samantha Stosur in the 2010 final here.

Two-time Grand Slam runner-up Vera Zvonareva withdrew from the event shortly before her first-round match Monday, citing a right shoulder injury.

The 11th-seeded Russian was replaced in the draw by Kazakhstani lucky-loser Sesil Karatantcheva, who was a quarterfinalist at Roland Garros as a 15-year- old in 2005. Karatantcheva dismantled Hungarian Timea Babos 6-1, 6-0 on Monday.

Capable American Bethanie Mattek-Sands upset oft-injured 12th-seeded German Sabine Lisicki 6-4, 6-3; 15th-seeded Slovak Dominika Cibulkova, a semifinalist here in 2009, cruised past Kristina Mladenovic of France 6-2, 6-1; 18th-seeded Italian Flavia Pennetta overcame Taiwan's Su-Wei Hsieh 6-7 (3-7), 6-4, 6-2; and 19th-seeded former world No. 1 Jelena Jankovic of Serbia overcame Austrian Patricia Mayr-Achleitner 1-6, 6-1, 7-5. The former U.S. Open runner-up Jankovic is a three-time French Open semifinalist.

Meanwhile, 24th-seeded Czech Petra Cetkovska bested Romanian Simona Halep 6-1, 6-3; 27th-seeded Russian Nadia Petrova handled Czech Iveta Benesova 6-3, 6-3; 29th-seeded Spaniard Anabel Medina Garrigues beat British lucky-loser Laura Robson 6-2, 6-1; American teenager Lauren Davis doused 30th-seeded German Mona Barthel 6-1, 6-1; and 31st-seeded Chinese Zheng Jie got past France's Alize Cornet 6-4, 6-4. Halep was a runner-up in Brussels, while Cornet was a runner-up in Strasbourg last week.

American women were a perfect 10-0 over the first two days of this French fortnight.

The 2012 Roland Garros champ will pocket $1.57 million.