Sampras stunned by Mantilla

“It’s back to the drawing board,” said Sampras, who must have felt as if he had been transported to the slow clay court of Roland Garros as he seemed content retrieving the Spaniard’s heavy topspin blasts from the baseline in first set instead of seizing control of the points.

Sampras’s ouster left another Spaniard, Carlos Moya, in position to seize top ranking after the fourth seed repelled a strong challenge from former number one Jim Courier to score a 7-6 (8-6), 6-4 victory.

Three-time Wimbledon runner-up Goran Ivanisevic, the 14th seed, also was bitten by the upset bug. He was ousted by 18-year-old Belgian Xavier Malisse 7-6 (11-9), 6-3.

Moya has to reach the final to have a chance to surpass Sampras.

Playing in only his second event this year, sixth seed and defending champion Marcelo Rios, who has been nursing a back injury, was impressive in taking apart France’s Cedric Pioline 7-6, 6-1.

Rubin, Serena in semis

INDIAN WELLS: Unseeded Americans Chanda Rubin and Serena Williams played giant killer at the Evert Cup yesterday, advancing to the semifinals with straight-set upset wins.

The 26th-ranked Rubin claimed the biggest scalp on offer, picking off top seed and defending champion Martina Hingis 6-3, 7-6 (7-2).

The 17-year-old Serena extended her match winning streak to nine with a tough 7-5, 7-6 (7-1) win over sixth seed Mary Pierce of France.

The 20th-ranked Serena next faces 12th seed Sandrine Testud, a 6-1, 6-3 conqueror of Henieta Nagyova of Slovakia.

Rubin earned a semifinal date with former world number one Steffi Graf, who crushed Jana Novotna 6-2, 6-0 for her 29th win in 33 career meetings with the Czech serve and volleyer.