NEW YORK -- John Isner's money maker is his gargantuan serve, but on Tuesday that weapon surpassed itself.
The highest-ranked American man won 41 of 42 first-serve points in an otherwise routine 6-2, 6-3, 6-4 first-round victory over Malek Jaziri. That's a 98 percent success rate.
More than half of those points (24) were the result of aces, tied for the early tournament lead with Vasek Pospisil.
"Wow," Isner said, laughing in his postmatch interview, "I did not know that."
Has he ever been 100 percent?
"Yeah, I think a long time ago in Cincinnati I didn't lose a point on my first serve the whole match," Isner said, "but it probably wasn't as many points.
"Yeah, that's a nice little stat."
Isner couldn't quite remember which point he lost.
On the first serve of the match's fifth game, Isner pounded a 135 mph serve down the middle that Jaziri returned well. On the fifth stroke, Isner dumped a backhand into the net.
Isner stands 6-foot-10, and with the combination of his long right arm, racket and a modest 5- or 6-inch jump off the ground, he usually makes contact with the ball more than 11 feet above the court. Not only does this give him a better angle to get the serve in, it creates a crazy bounce that can sometimes be up around the receiver's eyes.
Isner's fastest serve at 141 mph is second to Milos Raonic's 147.
The No. 13 seed has had a pleasant summer, winning in Atlanta, then losing in the Washington, D.C., finals to Kei Nishikori. More recently, he made the Montreal quarters (losing to Jeremy Chardy) and lost in the first round at Cincinnati to fellow American Sam Querrey.
Isner, who usually plays his local tournament at Winston-Salem, passed this year, opting to rest instead.
"I played a lot of matches, which is a good thing," Isner said. "It was something like 14 matches in 16 or 17 days.
"I'm very fresh right now," Isner said. "That's what I wasn't in Cincy. It's very important."
At the US Open, where seven best-of-five matches are required of the winner, getting off the court quickly is essential. In recent years, Isner has tended to give away a set or two in the early rounds and been fatigued going forward. Oddly enough, he has lost his past three matches here to Philipp Kohlschreiber in the third round. Kohlschreiber was also a Tuesday winner, surviving fellow German Alexander Zverev in five sets.
The way the draw shapes up, Isner would see No. 2 seed and Tuesday winner Roger Federer -- or Kohlschreiber -- in the quarterfinals. Whom would he rather play?
"That's a good question, but I can't answer," Isner said. "I'm not that good to think ahead."
Fellow American Donald Young also isn't looking too far ahead; he was just happy to win Tuesday.
The 68th-ranked Young rallied to upset 11th-seeded Gilles Simon 2-6, 4-6, 6-4, 6-4, 6-4 in 3 hours, 34 minutes with a packed Court 17 urging him on.
"I was almost ready to go home there," said Young, who had never come back from a two-set deficit.
Kokkinakis was forced to retire trailing 2-0 in the fifth set due to leg cramps that began in the fourth with the 19-year-old up two sets to one.
Stan Wawrinka, who has been tied to Kokkinakis via the comments of fellow tour player Nick Kyrgios, was able to advance Tuesday in straight sets. The fifth-seeded Wawrinka put away Albert Ramos-Vinolas 7-4, 6-4, 7-6 (8-6).
Information from The Associated Press was used in this report.