PARIS: Never mind the 16 double faults, Kristina Mladenovic downed defending champion Garbine Muguruza 6-1 3-6 6-3, sending the Roland Garros crowd into raptures as their darling reached the quarter-finals of the French Open on Sunday.

After a jittery opening set, Spanish fourth seed Muguruza rallied but 13th-seeded Frenchwoman Mladenovic perfectly played the key points in the decider to set up a meeting with either Venus Williams or Timea Bascinszky.

Mladenovic, who has been hampered by back problems, leads the tournament in terms of double faults, having served 40 of them since it started. Even though she won on Sunday, she added a big contribution to that total.

'Kiki, Kiki!" yelled the crowd as Mladenovic, a player born of Serbian parents and who speaks good English and cheers herself up in Italian, negotiated her way through the tricky fourth-round match.

"I love you, too," she told the chanting crowd after the win on a sunbathed Court Suzanne Lenglen.

She paused.