French Open 2018: Petra Kvitova out as Simona Halep and Garbine Muguruza advance
|French Open 2018|
|Venue: Roland Garros, Paris Dates: 27 May-10 June|
|Coverage: Daily live radio and text commentaries on BBC Radio 5 live, the BBC Sport website and app.|
Two-time Wimbledon champion Petra Kvitova was knocked out of the French Open, as world number one Simona Halep progressed to the last 16 on Saturday.
Czech eighth seed Kvitova, who was among the favourites after winning the Madrid Open, was beaten 7-6 (8-6) 7-6 (7-4) by Estonia's Anett Kontaveit.
Halep defeated German Andrea Petkovic 7-5 6-0 at Roland Garros in Paris.
Garbine Muguruza, the 2016 French Open champion, saw off Australia's Sam Stosur 6-0 6-2 in 63 minutes.
Serena Williams plays later on Saturday.
Kvitova broke Kontaveit's serve in the first game but paid the price for an erratic performance as her 13-match winning streak came to an end.
The 28-year-old, who suffered a career-threatening hand injury in a knife attack in December 2016, made 57 unforced errors and served 10 double faults against the 25th seed.
Kontaveit will play US Open champion Sloane Stephens in the last 16 after the American 10th seed beat Italy's Camila Giorgi 4-6 6-1 8-6 in an enthralling encounter lasting almost two and a half hours.
By contrast, Muguruza sealed her place in the fourth round in just over an hour against former US Open champion Stosur.
She raced through the first set and, although she was broken in the fourth game of the second, she won four games in a row to wrap up the match.
"I had a tough opponent - she's a Grand Slam champion and a former finalist here," Muguruza said.
"I knew that if I didn't play my best tennis it would be very hard."
Top seed Halep, twice a French Open runner-up, found herself out on Court 18 for the third-round meeting with Petkovic.
The experienced Petkovic kept things close in the first set, but had to have her knee strapped in the second as Halep raced away without dropping a game.
The Romanian will now face Elise Mertens in the fourth round after the Belgian 16th seed knocked out Daria Gavrilova 6-3 6-1.