Andy Roddick sent down 16 aces to beat Paradorn Srichaphan in straight sets and win the RCA Championship in Indianapolis.
The top seed won 7-6 6-4 to give him his third title of the year after wins at St Poelten on clay and on grass at Queen's Club.
Roddick also improved to 15-1 with coach Brad Gilbert, who
used to work with Andre Agassi and who teamed up after
Roddick lost in the first round of the French Open.
The beaten Wimbledon finalist let his concentration slip when he was leading 4-3 in the first set and a sponsorship sign fell and disrupted a rally.
The American screamed and smacked the ball high into the air and Srichaphan won the next two points to get to 4-4.
Two games later and leading 5-4, Roddick stirred up the crowd by arguing with the chair umpire when he thought a serve by Srichaphan was wide.
Roddick knocked his racket on the court and yelled at the umpire and ended up losing the game but kept his cool, finishing the resulting tiebreaker with an ace.
He made relatively quick work of Srichaphan in the second
set, losing just one point in his final four service games
of the match.
It was an ominous demonstration of form in the run-up to the US Open, where he will start one of the favourites.
"I never like saying I'm playing my best because, hopefully, two days from now I'll be playing better," said Roddick, who has now won six of his eight career titles in the US.
"I think at Queen's and Wimbledon, I was playing close to my best. It's definitely been exciting these past couple of months."