Winston-Salem, NC (Sports Network) - Reigning champion John Isner outlasted top-seeded Jo-Wilfried Tsonga in Friday's first semifinal at the $550,000 Winston-Salem Open, a final U.S. Open tune-up.

The third-seeded North Carolina native Isner improved to 9-0 at this event with a 6-4, 3-6, 7-6 (7-3) victory over the former Australian Open runner-up Tsonga on the hardcourts at Wake Forest University.

Tsonga managed to connect on only 1-of-10 break-point chances on Day 6, as the massive-serving Isner launched 24 aces and prevailed in 2 hours, 12 minutes. The towering American is now 3-1 lifetime against the Frenchman, who also lost to Isner in Davis Cup match in France earlier this year.

Isner will meet the Tomas Berdych-Sam Querrey victor in Saturday's final. Berdych is a former Wimbledon runner-up, while the surging Querrey titled on a hardcourt in Los Angeles last month and has won 13 of his last 16 matches on the ATP World Tour.

The 6-foot-9 Isner beat Frenchman Julien Benneteau in last year's Winston- Salem finale.

Isner will appear in his 12th career final, seeking a fifth championship. He titled in Newport last month and is also a two-time runner-up in 2012.

Saturday's champion will collect $73,930.