Sampras, who had minor foot surgery on July 15, will cede his No 1 ranking to Chile's Marcelo Rios if he loses in Toronto. Sampras is on course for a quarter-final match with Andre Agassi, the eighth seed.

The flamboyant Agassi kept pace, downing France's Guillaume Raoux 6-4, 7-5 in a hard-hitting baseline battle.

Other seeds advancing were: No 9 Alberto Costa of Spain, No 10 Goran Ivanisevic of Croatia and No 14 Mark Philippoussis of Australia. No 15 Fabrice Santoro of France lost 7-6 (10-8), 6-2 to Germany's Tommy Haas.

Fourth-seeded Monica Seles won a wild 7-6 (7-5), 7-5 second-round match over France's Sandrine Testud in the featured night match. In other second-round matches, top-seeded Martina Hingis scored a 6-3, 6-2 win over Natasha Zvereva of Belarus, unseeded Mary Pierce of France upset No 5Conchita Martinez of Spain 6-7 (1-7), 6-2, 6-3.

Kucera prevails

AMSTERDAM: Top-seeded Slovakian Karol Kucera has claimed a quarterfinal berth in the clay court Grolsch Open, ousting Dane Thomas Larsen, 7-5, 6-3.

But Romanian qualifier Adrian Voinea came back from a set down in his second round match to upset third-seeded Magnus Gustafsson of Sweden, 4-6, 6-1, 6-3 yesterday. Morrocan Hicham Arazi, who was disqualified on Tuesday for unsportsmanlike conduct in his match against Swede Magnus Norman, is to lose his prize money of $ 4,770.

O'Brien moves up

TORONTO: Alex O'Brien, who qualified for the main draw when Thomas Enqvist withdrew, upset Gustavo Kuerten 6-3, 7-6 (7-2) at the $ 2.4 million Du Maurier Open. O'Brien had to retire during qualifying on Sunday because of cramps. But when Enqvist, the No 12 seed pulled out, O'Brien made the field as the top-ranked qualifying loser.

Capriati knocked out

CARLSBAD (CALIFORNIA): The latest comeback attempt of Jennifer Capriati againended in the first round. Capriati, a teen phenom on the WTA Tour in the early 1990s, was beaten 5-7, 6-2, 6-2 by Ai Sugiyama of Japan yesterday in the $ 450,000 Toshiba Tennis Classic at the La Costa Resort and Spa.