Sampras, the world No 1, saved a match point in the third set before overcoming the Australian Mark Woodforde 6-7, 7-5, 7-6. After also losing a first-set tie-break, Agassi, the world No 7, took control of his match against a qualifier and fellow American Alex O'Brien to win 6-7, 6-3, 6-0.
Krajicek, the seventh seed, fell 7-6, 6-2 to the 10th-seeded Thomas Enqvist of Sweden, the Dutchman enduring problems with his first serve throughout the match.
Agassi, criticised for his on-court behaviour at the Olympics, became infuriated when he lost the opening set, walking to his courtside chair and smashing his racket on the ground. His actions went unpunished by the umpire. "He should have had a point penalty for that, but everyone is afraid of him," O'Brien said. "He can do anything he wants; he's the king. That's just the way it is."
Agassi said he was glad he had lost his temper. "I wanted to win the match. I was trying to get angry to get myself back into it again. It was a good mad."
After a see-sawing first set, the top-seeded Monica Seles of the United States took control and defeated the ninth-seeded Gabriela Sabatini of Argentina, 7-6 6-1, to move into the quarter-finals of the Canadian Open in Montreal. The No 2 seed, Arantxa Sanchez Vicario of Spain, received treatment for a strained forearm muscle when leading 3-2 in the first set of her match against the South African, Amanda Coetzer. Sanchez Vicario won 7-5, 6-1.
Amy Frazier of the US, the No 13 seed, surprised by beating the No 8 seed, Mary Pierce of France, 6-3, 6-3, and the sixth-seeded Magdalena Maleeva of Bulgaria won 6-3, 3-2 over Jennifer Capriati, who had to retire with a side strain.
After trailing 3-5 in the first set, Sabatini rallied to a 4-2 lead in the tie-break before going down. The second set, and the match, then fell quickly to Seles.Reuse content