Updated

Salem, NC (Sports Network) - John Isner upset Andy Roddick in American semifinal at the inaugural Winston-Salem Open, which is a final tuneup for the U.S. Open.

The fourth-seeded Isner upended the top-seeded Roddick in 7-6 (9-7), 6-4 fashion on the hardcourts at Wake Forest University.

Isner, who hails from nearby Greensboro, North Carolina, erased the struggling former world No. 1 Roddick in 1 hour, 34 minutes, as the two men combined for 18 aces, including 10 from the Day-6 loser.

The 6-foot-9 Isner is now 2-3 lifetime against Roddick, who prevailed in a bout at Indian Wells earlier this season.

Roddick hasn't reached a final since titling in Memphis back in February.

The 26-year-old Isner will appear in his eighth career ATP final, seeking a third title. The towering American captured a championship in Newport and was a runner-up in Atlanta last month.

Isner will face the Robin Haase-Julien Benneteau winner in Saturday's final, with the champion collecting $74,630.