WINSTON-SALEM, N.C. (AP) -- Andy Roddick came to North Carolina hoping for some good workouts before the U.S. Open. So far, he hasn't been seriously tested.
Roddick advanced to the quarterfinals of the Winston-Salem Open on Wednesday night,by beating Santiago Giraldo 6-1, 6-3.
Playing in the final men's tuneup before the U.S. Open, Roddick showed sharp form for the second match in a row.
In the process, he showed signs that he might be recovered from summer ailments in time for the final Grand Slam event of the year. This was just his third match in the last six weeks because of an abdominal strain.
"That's the biggest thing for me, not to be scared of extended rallies,'' Roddick said. "You have to get your legs back and there's only one way, and that's jumping in.''
Giraldo led the second set 2-1 before Roddick took the next three games to regain control.
Until this week, Roddick hadn't won a match since the second round of Wimbledon, recovering from an abdominal injury during much of that time. Now he has won on back-to-back nights.
"It's a thing where you crawl before you walk,'' Roddick said.
Roddick will face Juan Monaco on Thursday. Monaco, from Argentina, beat Kei Nishikori 6-0, 6-3.
Roddick needed slightly more than an hour to beat Giraldo, then said he's still trying to find the right pace, and that's something that will take time.
It was the first meeting between Roddick and Giraldo, a 23-year-old Colombian. Giraldo didn't threaten to break Roddick's serve and seemed off balance for most of the match.
Roddick and local favorite John Isner are the lone Americans remaining in the field, and they could meet in the semifinals.
Isner, the No. 4 seed, beat 13th-seeded Jarkko Nieminen 7-6 (4), 6-2.
Isner, a native of nearby Greensboro, solved Nieminen's serve and needed just 23 minutes to win the second set.
"I held serve comfortably today, and that puts so much pressure on my opponents,'' Isner said. "Any guy with a big serve will tell you being able to get cheap points puts so much pressure on (the opponent).''
In the quarterfinals, Isner will face Marcos Baghdatis, who beat Steve Darcis 7-5, 6-0. Isner lost only seven points out of 51 on his serve. The match ended, appropriately, with an ace.
He said playing in the North Carolina Triad is a main reason he entered, and he's rejuvenated by being a fan favorite playing close to his hometown.
Third-seeded Alexandr Dolgopolov advanced to the quarterfinals by beating Bulgaria's Grigor Dimitrov 6-4, 1-6, 7-6 (7). He will face the Netherlands' Robin Haase, who defeated Pierre-Ludovic Duclos 6-4, 7-5.
Ninth-seeded Sergiy Stakhovsky upset No. 5 Nikolay Davydenko 6-4, 6-4 to reach the quarterfinals. He will face qualifier Julien Benneteau. The Frenchman beat Russia's Igor Andreev 2-6, 6-1, 7-6 (5).