Muguruza, Rogers into quarters, rain holds up others

Paris: Garbine Muguruza of Spain blazed into the French Open quarter-finals for the third straight year on Sunday, defeating former champion Svetlana Kuznetsova 6-3, 6-4.

The 22-year-old Venezuelan-born fourth seed will next play world number 108 Shelby Rogers of the United States who defeated Irina-Camelia Begu of Romania by the same score 6-3, 6-4.

The two other scheduled fourth round ties were left unfinished when heavy rain started to fall late in the evening.

At that point, second seed Agnieszka Radwanska was 6-2, 3-0 up on Bulgaria's Tsvetana Pironkova and sixth seed Simona Halep of Romania was leading Australian veteran Samantha Stosur 5-3.

"At the end it is always very tough. She is a player with a lot of experience and I just had to be there," said Muguruza of her win over Kuznetsova.

"Quarter-finals is a great run and I am looking forward to improving my (best) result here."

Muguruza is seen as one of the new stars of the women's game after a breakthrough season in 2015 when she was runner-up to Serena Williams at Wimbledon and made the semis at the WTA Finals.

But in 30-year-old Kuznetsova she was up against one of the wiliest and experienced players on the women's circuit with two Grand Slam titles to her name -- the 2004 US Open and the 2009 French Open.

Both players had early break points on a sparsely-filled Philippe Chatrier centre court in a match of high quality.

And it was the Spaniard who struck first in the eighth game powering in a fine backhand return past the Russian to move 5-3 up.

She then served out comfortably for the set in 46 minutes.

Muguruza kept up the pressure and broke Kuznetsova's serve twice at the start of the second set, although she dropped her own in between.

The Russian pulled back to level at 4-4, but it was Muguruza who rose to the occasion taking the next two games and clinching the win on her fifth match point.

Quarter-final opponent Rogers is just the ninth woman outside of the top 100 to make the last eight in Paris since 1983.

It will be her first appearance in a Grand Slam last-eight.

"It's incredible and I'm really happy that it didn't start raining," said Rogers who broke down in tears after the match and had to borrow a handkerchief from television interviewer Marion Bartoli, the former Wimbledon champion.

"I always dreamed of this when I was a little girl in Charleston but never really thought I would reach the quarter-finals in Paris."

Rogers has now beaten three seeds in her run at Roland Garros having seen off 17th seed Karolina Pliskova in the first round and 10th seed Petra Kvitova in the last 32.

- Former runners-up -

Halep's match with 32-year-old Stosur brought up a clash of two former runners-up

Stosur lost to Francesca Schiavone in the 2010 final and Halep lost to Maria Sharapova two years ago.

They have played each other seven times with Halep 4-3 ahead having won their last four encounters, the last of which was a 6-2, 6-0 pounding in the Madrid Open semi-finals earlier this month.

Radwanska, meanwhile, enjoyed a 9-2 career stranglehold on the 28-year-old Pironkova, who has reached the fourth round in Paris for the first time.

But the world number 102 has already knocked out two seeds on her way to the last-16 -- Sara Errani and Sloane Stephens.

Radwanska, a Wimbledon finalist in 2012, is seeking to reach the last eight at Roland Garros for just the second time.

The biggest win of her career came in Singapore late last year when she won the season-ending WTA Finals.