The 116th-ranked Marat Safin came through 3-6 7-6 (7/5), 3-6 6-1 6-4 against the eighth-seeded Kuerten in 167 minutes.

He now plays Daniel Vacek of the Czech Republic after becoming the first qualifier in the history of the tournament to beat a defending champion.

"I am playing unbelievably at the moment," said Safin. "I start to hit and everything goes in. It's just luck. Maybe on the next day I will hit everything out. It's impossible for me to play better."

'Not too disappointed'

Kuerten was the second men's seed to be beaten today after fourth seed Patrick Rafter went out to fellow Australian Jason Stoltenberg 6-4 2-6 6-3 6-2.

"It's tough to come back and defend your title," said Kuerten.

"It's tough to lose but I can't be too disappointed. We both had chances to win, and in a fifth set anything can happen. I am playing well."

Varying fortunes for seeds

So far eight of the 16 men's seeds have failed to survive the first week at Roland Garros. The others to disappear have been Pete Sampras, Karol Kucera, Jonas Bjorkman, Greg Rusedski, Yevgeny Kafelnikov and Petr Korda.

Sampras: already out

The 1989 champion Michael Chang reached the third round after Dutch qualifier Johan Van Lottum retired with a strained thigh muscle.

This year's title favourite Marcelo Rios had a lucky escape - he was 6-1 3-3 down when South African Wayne Ferreira twisted his ankle and pulled out.

Rios is the first man to reach this year's fourth round in Paris. He could overtake Pete Sampras as world number one if he makes the semi-finals at Roland Garros.

Spain's Carlos Moya reached the last 16 when he beat Australian Andrew Ilie in straight sets while Brazilian Fernando Meligeni added to Australian woe by beating Todd Woodbridge.

Other winners included seeded Spaniards Alex Corretja, the number 14, and Alberto Berasategui, the number 16.

Hingis through easily

Hingis: two-set victory

In the women's championship Hingis, the world number one, beat Karina Habsudova of Slovakia 6-3 6-2 in 55 minutes, to book a last-16 showdown with Israel's Anna Smashnova.

Defending champion Iva Majoli notched up a 6-3 6-4 victory over Natasha Zevereva of Belarus.

There were no surprises with American Venus Williams eliminated Alexia Dechaume-Balleret 6-2 6-1.

Three-times champion Monica Seles reached the last 16 when she scored a straight-sets victory over Austria's Barbara Swartz.

Teenage Russian Anna Kournikova beat Asa Carlsson 6-0 6-0 in 49 minutes. She now plays third seed Jana Novotna, who beat Elena Tatarkova from the Ukraine 6-3 7-6 (7/5).