Top seed Andre Agassi has reached the quarterfinals of the Legg Mason Tennis Classic here in Washington. But defending champion Andy Roddick is out of the event.

Andre Agassi has won this tournament five times before, and uses the event as a key warm-up for the U.S. Open.

The 32-year-old American won the first set with 170th ranked Brian Vahaly 6-1. However, the University of Virginia player gave Agassi a tough match, taking the second set to a tiebreaker before Agassi won, 7-6. Vahaly was cheered by several of his college fans, and Agassi gave him plenty of credit. "He gave them a great show too," he said. "I thought he played a high standard match. He had to really hang in there with the way I came out of the blocks and he did that well. He is a good competitor and he was making the match more difficult than the crowd was."

Agassi will next take on Thomas Enqvist of Sweden, the seventh seed, who scored a straight-set win over German Lars Burgsmuller (6-3, 7-5).

Spanish fourth seed and former champion Alex Corretja scored a straight-set win over Karol Kucera of Slovakia, 6-1, 6-1. He next takes on American James Blake, a straight set winner over Guillermo Coria of Argentina (6-4, 7-5).

Thailand's Paradorn Srichaphan defeated last year's runner up Sjeng Schalken of the Netherlands in three sets (4-6, 6-2, 6-4). He takes on Finland's Jarkko Niminen, a three-set winner over American Alex Kim (0-6, 6-4, 6-3).

Chilean Marcelo Rios scored a straight-set win over Jerome Golmard of France (6-3, 6-1). He faces another South American, Fernando Meligeni of Brazil, who scored a straight-set win over defending champion and second seed Andy Roddick of the United States.