New Haven, CT -- (Sports Network) - Fourth-seeded Russian Igor Andreev, second- seeded Croat Ivo Karlovic and eighth-seeded American Mardy Fish were second- round winners Tuesday at the $708,000 Pilot Pen Tennis event, a final U.S. Open tune-up.

Andreev erased Belgian Olivier Rochus 6-3, 6-4 on the hardcourts at the Connecticut Tennis Center.

Fish, who was last year's New Haven runner-up to fellow American James Blake, bounced back from a second-set loss to compatriot Wayne Odesnik to take a 6-1, 4-6, 6-1 victory.

Karlovic dropped his first set to American John Isner, but then easily handled the next two sets to take a 6-7 (4-7), 6-3, 6-4 victory.

German Mischa Zverev toppled fifth-seeded Argentine Juan Monaco 6-3, 6-3, while No. 6 seed Marin Cilic of Croatia was leading last week's Washington, D.C. runner-up Viktor Troicki, 2-1, when the Serbian retired.

In additional action involving top-10 seeds, No. 7 Italian Andreas Seppi overcame compatriot Potito Starace 4-6, 6-4, 6-4; No. 9 Frenchman Marc Gicquel grounded Spaniard Albert Montanes 7-5, 6-3; and Fabio Fognini upended 10th- seeded fellow Italian Simone Bolelli 6-2, 5-7, 6-4.

Eleventh-seeded Austrian Jurgen Melzer snuck past pesky French veteran Arnaud Clement 7-6 (7-1), 7-5 on the grounds at Yale University.

American wild card Robby Ginepri posted an upset by taking out 12th-seeded Argentine Agustin Calleri 6-2, 4-6, 6-2, while other upsets came when Belgian Steve Darcis drove out 13th-seeded Spaniard Marcel Granollers 6-2, 6-2; Slovenian qualifier Luka Gregorc knocked out 14th-seeded Argentine Jose Acasuso 6-4, 6-4; and Czech Ivo Minar doused 15th-seeded Argentine Eduardo Schwank 7-5, 6-3. Minar is rewarded with a third-rounder against top-seeded Fernando Verdasco of Spain.

Sixteenth-seeded Romanian Victor Hanescu avoided an upset by holding off German Denis Gremelmayr 6-7 (5-7), 7-6 (7-3), 6-2.

An additional second-round win came for American lucky-loser Jesse Levine, who drubbed Spaniard Guillermo Garcia-Lopez 6-0, 6-3. Levine joined the draw on Monday when red-hot Argentine Juan Martin del Potro withdrew, citing exhaustion.

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