Defending champion Li Na suffered the shock of the tournament after she was sent crashing out of the French Open in the fourth round.

World No. 142 Yaroslava Shvedova, who went through qualifying to snatch a spot in the main draw at Roland Garros, earned a 3-6 6-2 6-0 triumph against the seventh seed.

Li, the 30-year-old world No. 7, was attempting to be the first French Open women's champion to successfully defend the title since Justine Henin in 2007.

After a confident start, Li had a spectacular meltdown in the second set and never recovered, notching 41 errors and ending up broken seven times by her 26-year-old opponent.

Li, however, joins Azarenka, Serena and Venus Williams, Caroline Wozniacki and Agnieszka Radwanska among the big-name casualties.

Shvedova had also made it to the Roland Garros quarterfinals in 2010, her first time in a grand slam last eight, and was the sole qualifier remaining in the women's draw when she beat Li.

"I will take some days off to totally forget tennis, then try to come back next week," said Li, who has not won a title since her Paris triumph 12 months ago.

"I need some time to recover - I'm not a machine. I just tried to play the ball back to the court, but I couldn't. I will find out why. But not today."