Defending champion Li Na crashed out of the French Open on Monday while Maria Sharapova survived a deluge of errors on a bitterly cold day in Paris to struggle into the quarterfinals.

Li, who was Asia's first Grand Slam singles champion when she took the 2011 title, lost her crown at the fourth round stage, going down 3-6, 6-2, 6-0 to Kazakh qualifier Yaroslava Shvedova, the world 142.

World number seven Li was attempting to be the first French Open women's champion to successfully defend the title since Justine Henin in 2007.

But after a confident start on Suzanne Lenglen court, the 30-year-old Chinese endured a spectacular meltdown in the second set and never recovered, notching 41 errors and ending up being broken seven times by her 24-year-old opponent.

"I lost one match so don't try to put me down," Li, who hasn't won a title since her Paris victory, snapped at a tense post-match news conference.

"This is tennis. I will try to find the reason why I lost."

Shvedova, who was a quarterfinalist in 2010, had to come through qualifying after a knee injury in 2011 saw her ranking plummet to 206.

She will now face either fourth-seeded Wimbledon champion Petra Kvitova or unseeded American Varvara Lepchenko for a place in the semi-finals.

"I was nervous in the first set and was making mistakes, but I then tried to attack more," said Shvedova.

"I knew she was the defending champion and she had all the pressure. I had come from qualifying, was playing my seventh match and I just told myself to enjoy the day and try and my best."

Sharapova struggled into the quarterfinals, defeating Czech veteran Klara Zakopalova 6-4, 6-7 (5/7), 6-2 in an error-scarred clash which featured 21 breaks of serve.

The Russian second seed, seeking a Roland Garros title to complete a career Grand Slam, goes on to face either Estonian 23rd seed Kaia Kanepi or Arantxa Rus of the Netherlands for a place in the semifinals.

But she will be hoping for an improvement in conditions in Wednesday's quarter-final after a stiff wind and bitter cold, which saw temperatures dip to a chilly 14 degrees, played havoc with her game, temper and movement.

The statistics of Monday's match on Philippe Chatrier court told a grim tale.

Sharapova finished with 53 unforced errors to her opponent's 48 and served up 12 double faults against seven.

With serve constantly under siege, Sharapova carved out a massive 31 break points in total, converting 12.

"She played extremely well, she's a dangerous player," said Sharapova of an opponent she had beaten in straight sets on clay in Madrid last month.

"The conditions were difficult, but it was a good test for me. I had the chance to finish it in two sets. I came out strong in the third and it's nice to be in the quarters again."

Sharapova, twice a semifinalist and the favourite for the title following the exits of top seed Victoria Azarenka, Li and Serena Williams, rarely settled in the three hour 11 minute encounter.

Twice she argued with umpire Julie Kjendlie while also taking an embarrassing, bottom-first tumble on to the damp red clay midway during the ninth game of the second set.

In a neat snapshot of the match, Sharapova double-faulted on match point in the seventh game of the final set; Zakopalova suffered a similar lapse in the next game to hand her opponent victory.