WINSTON-SALEM, N.C. — Top-seeded Andy Roddick rolled to a 6-1, 6-4 victory over Argentina's Juan Monaco on Thursday afternoon in the Winston-Salem Open quarterfinals.

WINSTON-SALEM, N.C. — Top-seeded Andy Roddick rolled to a 6-1, 6-4 victory over Argentina's Juan Monaco on Thursday afternoon in the Winston-Salem Open quarterfinals.

Roddick will take on fellow American John Isner in today's semifinals. Isner rallied past eighth-seeded Marcos Baghdatis of Cyprus 1-6, 6-3, 6-4 earlier Thursday.

Roddick needed just more than an hour on a hot afternoon as he dominated with his serve, getting his first serve in 81 percent of the time.

In the other quarterfinal matches, France's Julien Bennetau, a qualifier, rallied from a set down to beat ninth-seeded Sergiy Stakhovsky of Ukraine 3-6, 7-6 (9), 6-2 and 10th-seeded Robin Haase of the Netherlands beat Ukraine's Alexandr Dolgopolov 6-4, 6-4 in a match that lasted 1 hour.

Bennetau and the 24-year-old Haase, who is ranked 42nd by the ATP, will play the second semifinal. The final is scheduled for Saturday.

New Haven Open

At New Haven, Conn., top-ranked Caroline Wozniacki advanced to the semifinals of the New Haven Open with a 7-5, 6-3 win over 19-year-old American Christina McHale.

Wozniacki is 15-0 at the WTA's final tuneup before the U.S. Open and is the tournament's three-time defending champion.

Wozniacki's semifinal opponent will be third-seeded Francesca Schiavone, who advanced when Anabel Medina Garrigues withdrew due to a knee injury.

Second-seed Li Na endured several hours of rain delays and three sets of tennis before advancing in her quarterfinal, 6-4, 3-6, 6-2, over Russia's Anastasia Pavlyuchenkova. Li will play Czech qualifier Petra Cetkovska who beat fourth-seed Marion Bartoli 7-5, 7-5.