Former French Open champion Li Na was dumped out of the French Open in the second round by a resurgent Bethanie Mattek-Sands today.

The American, more famous for her headline-making fashion statements than her tennis, recovered from a set down to win 5-7 6-3 6-2.

Two summers ago Mattek-Sands was ranked in the top 30 but last year came a slump that dropped her outside 200 in the rankings.

She was still ranked that low in February but began her climb back with a run to the final of the tournament in Kuala Lumpur and has really hit form on the clay.

The 28-year-old came through qualifying in Stuttgart last month and reached the semi-finals, beating last year's French Open runner-up Sara Errani on the way, and today's win over the sixth seed means she has already equalled her best run at Roland Garros.

Li, who beat Francesca Schiavone in the final two years ago, was the player who ended Mattek-Sands' run in Stuttgart but she was out-hit today.

The American served for the match for the first time at 5-0 in the decider only for Li to pull two games back, but her comeback ended there.

The match finished in heavy rain having been twice disrupted, but Li was left scratching her head for answers.

"If I knew for sure, I would not lose seven games in a row. This is very tough conditions, going back to the court three times," Li said.

"But for both players it's the same, so I should find out what happened and talk to myself and also talk to team to see what happened."

Li admitted the level of Mattek-Sands' play had shocked her, saying: "I was a little bit surprised the way she's hitting on the court. Well done to her. Good luck for her, as well."

There were no such worries for ninth seed Sam Stosur, who wrapped up her 6-4 6-3 victory over Frenchwoman Kristina Mladenovic just before rain began to fall for a second time.

Stosur, who will meet Jelena Jankovic next, is regarded as a particularly dangerous player on clay and reached the French Open final in 2010.

But it has not always been like that, and the Australian said: "I didn't play on clay at all until I was 15.

"I went on a junior trip to Europe, and we had five weeks, I think, on clay. I didn't win a match and I hated every second of it.

"So I certainly didn't like it those first few years when I played because simply I had no idea what I was doing. And I wasn't as consistent as I am now. But probably the last five years I have really enjoyed it."

Jankovic was even quicker, winning the final 12 games to defeat Spanish teenager Garbine Muguruza 6-3 6-0, while 17th seed Sloane Stephens eased past fellow American Vania King.

Meanwhile, Maria Sharapova led Eugenie Bouchard 6-2 4-2 when the over-worked groundstaff hauled the green court covers over for the last time at 2100 local time.