PHOTOS: Azarenka, Kuznetsova knocked out of French Open
World number one Victoria Azarenka was knocked out in the fourth round of the French Open when she slumped to a 6-2, 7-6 defeat by Slovakian 15th seed Dominika Cibulkova on Sunday.
Belarussian Azarenka, who lost the tiebreak 7-4, will lose her world number one spot to Maria Sharapova if the Russian second seed reaches the final.
Cibulkova, who reached the semi-finals at Roland Garros in 2009, threw her racket and fell on her back after ending Azarenka's run with a backhand crosscourt passing shot after one hour and 47 minutes.
She will next meet either American teenager Sloane Stephens or Australian sixth seed Samantha Stosur.
Image: Dominika Cibulkova of Slovakia reacts after winning her match against Victoria Azarenka of Belarus during the French Open
Errani reaches French last eight
Italy's Sara Errani became the first woman into the French Open quarter-finals when she knocked out former champion Svetlana Kuznetsova of Russia 6-0, 7-5 on Sunday.
Claycourt specialist Errani, who had never gone beyond the second round at Roland Garros before this year, reeled off the first eight games before Kuznetsova won her first game, on a break.
Kuznetsova, the 2009 champion who had beaten Errani in five previous meetings, hit a succession of shots into the net to give away matchpoint in the 12th game and then put a forehand wide.
Errani, seeded 21st, will now meet 10th-seeded German Angelique Kerber.
Image: Svetlana Kuznetsova of Russia leaves the court after losing her match against Sara Errani of Italy during the French Open
Kerber reaches quarter-finals for first time
German 10th seed Angelique Kerber bludgeoned her way into the French Open quarter-finals for the first time with a 6-3 7-5 win over Croatian Petra Martic on Sunday.
Kerber made an impressive run to reach the U.S. Open semi-finals last year and has a chance to match or even improve on that result after dispatching her 21-year-old opponent on a dark and gloomy Suzanne Lenglen court.
With the heavens threatening to open at any time, a muttering Kerber did not want to hang around longer than necessary and yelled out an almighty "Come on" after she fired down a backhand winner on her third matchpoint.
Image: Angelique Kerber of Germany returns the ball to Petra Martic of Croatia during the French Open
Djokovic prevails over Seppi
Novak Djokovic completed a remarkable escape act to move into the quarter-finals of the French Open, hauling himself back from two sets down to beat unfancied Italian Andreas Seppi 4-6, 6-7, 6-3, 7-5 6-3.
The world number one had looked down and out as he racked up a catalogue of unforced errors under a leaden Parisian sky to fall towards the precipice of an early exit.
A lacklustre Djokovic, however, got the upper hand in the third and began to wear down his opponent before closing out the match in four hours 18 minutes.
Djokovic, who is looking to complete his haul of grand slam trophies, will play the winner of Stanislas Wawrinka's fourth round clash with fifth seed Jo-Wilfried Tsonga.
Image: Novak Djokovic of Serbia reacts during his match against Andreas Seppi of Italy during the French Open
Federer beats fan Goffin to reach quarters
Roger Federer surrendered one set against Belgian fan and newcomer David Goffin before beating the lucky loser 5-7, 7-5, 6-2, 6-4 to reach the quarter-finals of the French Open on Sunday.
Federer, seeking a record 17th grand-slam title, will play either Argentine Juan Martin del Potro, the ninth seed, or number seven Tomas Berdych of Czech Republic in the last eight.
The Swiss, who won the Roland Garros title in 2009, saved two breakpoints before surrendering a third on a forehand error to lose the first set.
The 21-year-old Goffin, the first lucky loser to reach the last 16 of a grand slam since compatriot Dick Norman at Wimbledon in 1995, kept up the pressure but ultimately was no match for the wily Federer.
Image: Roger Federer of Switzerland (L) shakes hands with David Goffin of Belgium after winning his match during the French Open