SAN JOSE, Calif. -- On one of the most important points of the match, John Isner walked up to the baseline, bounced the ball between his legs and wasted no time smacking an adrenaline-fueled 138 mph ace.
So long, break point.
So long, set point.
So long, any questions about whether his serve is back.
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 bone bruise in his right knee that forced him to drop out of last month's Australian Open is no longer an issue, and apparently neither is his confidence.
"It's not something I'm going to just try to kick a serve in," Isner said. "I'm going to go for it."
The highest-ranked American saved two break points on his serve in a lengthy first-set tiebreaker, relied on his big-finish forehand for two breaks in the second set and never let his strongest stroke 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. He improved to 5-2 in his career in San Jose. His previous best finish at the tournament played on a hard court in the home of the NHL's San Jose Sharks had come in 2008, when he lost in the quarterfinals to Guillermo Garcia-Lopez.
"If I serve well," Isner said, "I can be in the match against anybody in the world."
The hard-hitting headliner put his favorite stroke all over his latest match.
Neither player faced -- nor forced -- a break point in the first set until the tiebreaker, and Isner never faced one after that. The 6-foot-9 American, ranked No. 16 in the world, kept the rallies short and the time between points even shorter and relied on his serve in the most critical moments of the match.
Malisse took a 3-0 lead in the tiebreaker before Isner smacked a return on the baseline that sent the Belgian backpedaling for a backhand that landed in the net to tie the score 5-all. Both times Malisse earned a set point, he couldn't solve Isner's serve, including a match-high 138 mph ace out wide.
Isner finally flicked a forehand from the baseline at the feet of a charging Malisse on his second set point. Malisse netted the in-between backhand, and Isner pumped his fist all the way to the bench.
"I just tried to hit my biggest serves," Isner said. "I feel like when I am serving out a set or serving out a match, I'm up a break, I feel like that's when my sense of urgency is the best. Essentially, I don't want to hit a ball besides my serve."
After the tiebreaker, he hardly did.
The only other drama came three games later, when Isner challenged a called ace by Malisse that was overruled. Isner later went ahead 15-40 and forced another backhand in the net for a break and a 2-1 lead that had the American screaming "Come on!"
Isner earned another break and cruised comfortably on his serve. On match point, he served out wide and put away an easy volley with Malisse well off the court.
After dropping the first two meetings, Isner has won the last three against Malisse. He's also starting to regain his rhythm after stumbling late last year, leaving Australia with a nagging knee and looking rusty earlier this week.
Isner had lost to Thomaz Bellucci to send the U.S. and Brazil to a deciding fifth match Sunday, when Sam Querrey sealed the victory for the Americans by beating Thiago Alves indoors in Jacksonville, Fla. Isner hadn't played on the ATP World Tour since a two-set loss to fellow American Ryan Harrison in the second round in Sydney on Jan. 9, and he's hoping to regain his rhythm before the summer season.
Since losing in the round of 32 in the U.S. Open last August, Isner entered San Jose 3-7.
"It's a gradual thing, and winning cures a lot of issues for me," Isner said. "Mainly with confidence and being comfortable on the court, and that's what I feel like I'm building toward."
After two wins to advance to the semifinals, Haas and the rest of the field will give Isner tougher competition.
Top seed and two-time defending tournament champion Milos Raonic of Canada was scheduled to play Denis Istomin in the night session. Querrey, seeded third, was facing Colombia's Alejandro Falla in the late match.