Henri Leconte of France, playing inspired tennis reminiscent of last year's Davis Cup final, defeated No. 2 seeded Pete Sampras, 6-3, 7-5, in the second round of the Paris Open on Wednesday.
Sampras' Davis Cup teammates, Andre Agassi and John McEnroe, also lost.
Brad Gilbert, a two-time Paris Open finalist, upset the seventh-seeded Agassi, 6-1, 6-2, and No. 9 Boris Becker defeated McEnroe, 6-4, 6-4.
With the crowd cheering as it did at the Davis Cup at Lyon, Leconte beat Sampras for the second time in three meetings.
"The crowd was a little like the Davis Cup, and I played the same," Sampras said.
"I didn't have it today. He played with a lot of emotion, and I played with no emotion. A lot has to do with the crowd. If I played Henri anywhere else but in France, the result would be different."
Leconte also played with inspiration at last summer's French Open, where he advanced to the semifinals before losing to Petr Korda of Czechoslovakia.
Four other seeded players lost second-round matches. Arnaud Boetsch of France beat No. 5 Korda, 7-5, 6-4; Wally Masur of Australia upset No. 15 Sergi Bruguera of Spain 6-3, 7-5; Jakob Hlasek of Switzerland beat No. 8 Wayne Ferreira of South Africa, 6-3, 3-6, 6-3, and Jim Grabb defeated No. 10 MaliVai Washington, 4-6, 6-4, 6-0.
Agassi, playing listlessly, lost in a little more than an hour. Agassi accepted a late wild-card bid to compete in this indoor tournament for the first time. He last played at Sydney three weeks ago.
Second-seeded Martina Navratilova defeated Nicole Provis, 6-1, 2-6, 6-1, and Croatia's top female player, 15-year-old Iva Majoli, upset fifth-seeded Lori McNeil, 6-3, 0-6, 6-2, to move to the quarterfinals of the $350,000 Bank of the West Classic at Oakland.
Also advancing to the quarterfinals was fourth-seeded Katrina Maleeva of Bulgaria, who shook off 10 double faults to beat Ann Grossman, 6-4, 4-6, 6-3.