New Haven, CT -- (Sports Network) - Top-seeded Spaniard Fernando Verdasco was an easy third-round winner, while second-seeded Croat Ivo Karlovic went by way of the upset Wednesday at the $708,000 Pilot Pen Tennis event, a final U.S. Open tune-up.

Verdasco leveled Czech Ivo Minar 6-3, 6-1, while the 6-foot-10 Karlovic was upended by Slovenian qualifier Luka Gregorc 7-6 (7-4), 4-6, 6-2 on the hardcourts at the Connecticut Tennis Center.

Up next for Verdasco will be German Mischa Zverev in the quarterfinals.

In the late contest, eighth-seeded American Mardy Fish had an easy time dispatching ninth-seeded Marc Gicquel 6-4, 6-3. Fish was last year's New Haven runner-up to fellow American James Blake.

Fourth-seeded Russian Igor Andreev moved on by besting 16th-seeded Romanian Victor Hanescu 6-4, 7-5, while sixth-seeded Croat Marin Cilic overcame 11th- seeded Austrian Jurgen Melzer 5-7, 6-4, 7-5 and seventh-seeded Andreas Seppi subdued fellow Italian Fabio Fognini 6-4, 6-2 on the grounds at Yale University.

Also, American lucky-loser Jesse Levine was leading Steve Darcis 2-0 in the first set when the Belgian retired with a back injury, while the aforementioned Zverev erased American wild card Robby Ginepri 1-6, 6-3, 6-1 on Day 4.

The 2008 U.S. Open will commence Monday in New York.