Salem, NC (Sports Network) - Local favorite John Isner was a round victor Wednesday at the inaugural $553,125 Winston-Salem Open, a final hardcourt tuneup for the U.S. Open.

The fourth-seeded 6-foot-9 Isner, who hails from nearby Greensboro, North Carolina, ripped 10 aces and held his serve throughout in topping 13th-seeded Finnish veteran Jarkko Nieminen 7-6 (7-4), 6-2 at Wake Forest University.

Third-seeded Alexandr Dolgopolov moved into the quarterfinals with a 6-4, 1-6, 7-6 (9-7) victory over 14th-seeded promising Bulgarian Grigor Dimitrov, while ninth-seeded Ukrainian Sergiy Stakhovsky topped fifth-seeded struggling Russian Nikolay Davydenko 6-4, 6-4 on Day 4.

Tenth-seeded Dutchman Robin Haase handled Canadian lucky-loser Pierre-Ludovic Duclos 6-4, 7-5. The big-hitting Haase, who captured his first career title in Austria three weeks ago, will meet Dolgopolov on Thursday.

Another third-rounder saw French qualifier Julien Benneteau overcome Russian Igor Andreev 2-6, 6-1, 7-6 (7-5). Benneteau will encounter Stakhovsky in the round of eight.

The Winston-Salem champ will collect $74,630.