WINSTON-SALEM, N.C. (AP) -- Fourth-seeded John Isner upset top-seeded Andy Roddick 7-6 (7), 6-4 Friday in the semifinals of the Winston-Salem Open, a final tuneup before the U.S. Open.
Isner won the first set in a tiebreaker by breaking Roddick's serve to go up 8-7. He ended the set with a 107-mph serve.
The 28th-ranked Isner will play the winner of the match between Robin Haase and qualifier Julien Benneteau in Saturday's final.
The 21st-ranked Roddick, who had been 8-0 in his career in Winston-Salem, broke Isner in the second set to go up 3-1. But Isner came right back to break Roddick in the next game.
Tied at 4-4, Isner got another break to go up 5-4 and had three aces to end the match.
The 26-year-old Isner will be aiming for his third career ATP title on Saturday.