John Isner advanced to the SAP Open semifinals for the first time in his career Friday, overpowering Xavier Malisse 7-6 (8), 6-2 behind his booming serve.
The highest-ranked American saved two break points in a lengthy first-set tiebreaker, relied on his big-finish forehand for two breaks in the second set and never let his strong serve slip during a quick 68-minute match. He will play Saturday against fourth-seeded Tommy Haas, who beat wild-card Steve Johnson 6-4, 6-2.
Isner finished with 10 aces and no double-faults and made 67 percent of his first serves. Perhaps most importantly for Isner, the bone bruise in his right knee that kept him out of the Australian Open is no longer slowing him down.