Verdasco will play German Mischa Zverev in the quarterfinals. Zverev moved on with a 1-6, 6-3, 6-1 win over Robby Ginepri of the United States.
Slovenian qualifier Luka Gregorc upset second-seeded Ivo Karlovic of Croatia 7-6 (7-4), 4-6, 6-2.
Fourth-seeded Igor Andreev of Russia beat Romanian Victor Hanescu 6-4, 7-5.
American Mardy Fish, the No. 8 seed, topped France's Marc Gicquel 6-4, 6-3.
Others advancing included Marin Cilic of Croatia, Andreas Seppi of Italy and Jesse Levine of the United States.