World number one Victoria Azarenka is out of the French Open following a shock defeat by Dominika Cibulkova.
An out-of-form Azarenka, who almost lost to Alberta Brianti in the first round, went down 6-2 7-6 (7-4) against 15th seed Cibulkova of Slovakia.
The Australian Open champion now turns her focus to the grass court season, while Cibulkova faces Sam Stosur.
Stosur beat Sloane Stephens 7-5 6-4 while 2009 winner Svetlana Kuznetsova lost 6-0 7-5 to Sara Errani.
The Italian will play 10th seed Angelique Kerber, who defeated Petra Martic of Croatia 6-3 7-5.
Kuznetsova's exit means Li Na is the only former champion left in the draw.
Top seed Azarenka, 22, had beaten Cibulkova seven times in eight previous meetings - overturning a set and a break deficit in the last two.
But there would be no repeat on this occasion as the top seed joined Serena and Venus Williams, Caroline Wozniacki and Agnieszka Radwanska among the big-name casualties.
When asked what she planned to do after the defeat, Azarenka sarcastically responded: "I'm going to kill myself.
"This tournament is over for me. What's to recover from? It's [time] to really look forward and improve. That's it."
An enthralling 15-minute first game, which included six break points, went the Belarusian's way but after that Cibulkova took control.
The 5ft 3ins right-hander broke back immediately before going on to comfortably win the first set in 44 minutes.
Azarenka rallied to take a 2-0 lead in the second, but the diminutive Cibulkova showed her mental strength to run off four games in a row.
Azarenka's frustrations came to a head as she twice smashed her racquet against the clay court but she managed to fight back and level at 4-4 before going on to serve for the set.
However, Cibulkova broke serve to force a tie-break, which she led from the start to pull off a superb win.
Cibulkova, 23, can watch on as sixth seed Stosur and Stephens of the United States meet later on Sunday.
Errani's victory over Kuznetsova means she is through to the quarter-finals at Roland Garros for the first time in her career.
It has been a poor season for Kuznetsova, and she said: "Today the weather was so bad. I felt cold during the whole match.
"For me to move was really complicated. I could not make my feet work. I'm far away from my best form yet."