Delgado was 96 places below Sampras

Sampras does not like slow clay courts or heavy tennis balls, and the damp conditions played a massive part in his 7-6 6-3 6-4 humbling on Court Suzanne Lenglen.

He appeared to have a relatively simple passage into the third round against Delgado, ranked 96 places below him, and when leading the first set 4-1 he appeared to be in total control.

But when the rain started Sampras began to look increasingly uneasy and Delgado grew in confidence.

After a break of an hour Sampras was left shaking his head in disbelief as his normally rock-solid ground strokes began to spray long and wide.

As the light fell, a haggard-looking Sampras appeared to tire rapidly and when he lamely sliced match-point halfway up the net he was put out of his misery after two hours and three minutes.

Rios wants his number one slot back

"I thought my preparation was good, it's disappointing. Everyone knows I put a lot of emphasis on the majors and I came up short," he said.

"I'm just not playing well this year, plain and simple. But a lot of athletes go through periods where they don't play well.

"But they bounce back and that's what I have to do now at Wimbledon."

Chile's Marcelo Rios, who is hoping to take the world number one spot off sampras had an easy win, despite three rain breaks. He beat Spain's Emilio Alvarez in straight sets, 6-4 6-2 6-2.

The Scud misfired

But Jim Courier, who has won this tournament twice, lost badly to Jens Knippschild of Germany, 6-4, 6-2, 6-2.

Knippschild will now play Johan Van Herck of Belgium who defeated fifth-seed Greg Rusedski in the first round.

The big-serving Australian, Mark "Scud" Philippoussis threw away a two-set lead to lose a rain-interrupted five-set second round marathon against Czech Bohdan Ulihrach.

Hingis through

Martina Hingis has cruised into the third round of the French Open, beating German Meike Babel 6-1 6-2 in less than an hour.

Hingis is focussed on the French Open

Hingis, who is looking for the only grand slam title she has not yet won is on course for a potentially tricky quarter final clash with the rising American star Venus Williams, who beat her in straight sets in Indian Wells earlier this year.

"Of course some people beat me when I'm 50 percent. If I'm 100 percent, I think I can beat everybody still," she said.

"I'm feeling happy about the way I play. It's Kids Day. It was a wonderful atmosphere. I feel good," she said.

Williams, seeded eighth, lost just two games as she beat Japanese Ai Sugiyama, 6-0 6-2.

"I think I was playing better than what I did in the first round. She played well but I played a little better, and didn't miss."

But so is Williams

Williams is not worried about the potential quarter-final clash with Hingis, even though the world number one beat her in the final of the US open last year.

"I'm not thinking about the quarter-finals, I'm taking everything point by point right now, even shot by shot.

"To me it really doesn't matter who I play.

Elsewhere the third seed Jana Novotna of the Czech Republic struggled for a set against France's Emilie Loit before winning 7-5 6-0.

Monica Seles went through despite losing the first set of her second-round tie against South African Marion Maruska.