John Isner admitted the Winston-Salem Open final wasn't the best tennis he's played this season.

Still, the end result was just what Isner hoped for — another momentum-building victory heading into the U.S. Open.

Isner won his second straight Winston-Salem title Saturday, battling through a third-set tiebreaker to beat seventh-ranked Tomas Berdych of the Czech Republic 3-6, 6-4, 7-6 (11-9).

Isner had 22 aces, but needed to overcome his own mistakes for his second win this season and fifth career title in the final hard-court tournament before the U.S. Open.

"There were certainly some tense times all throughout the match," said Isner, who also won at Newport, R.I., last month. "At times, it wasn't the prettiest tennis, but I was able to gut it out. I'm very, very proud of that."

Berdych, playing in his third final this season, broke Isner's serve in winning the first set, and had three mini-breaks in the tiebreaker, the last giving him match point at 6-5.

But Isner broke Berdych on the next point to tie the score, and later went on to win the last three points.

"It was a point that I'm going to see for quite a long time," said Berdych, who is seeded sixth at the U.S. Open and will play Winston-Salem quarterfinalist David Goffin of Belgium in the first round.

"I hope there's going to be enough time to put this out of my mind, but remember all the matches before it, which were pretty good for me."

However, Isner had some lucky breaks.

Tied 9-9, Isner barely returned a hard crosscourt backhand, and was left out of position as Berdych approached the net. But Berdych's forehand hit the net cord and bounced out of bounds, giving Isner match point.

"I was prepared to all-out dive if that ball had made it over the net," Isner said.

On match point, Isner had to chase down a hard forehand and backhand from Berdych, putting both returns on the line. Isner then ripped his own hard forehand down the line to win the tiebreaker and the match.

"I just scrapped it out," Isner said. "It wasn't pretty, but he made a mistake at the end on a ball that he normally makes.

"I know I'm fortunate to have won this match. It could've easily gone the other way."

The 6-foot-9 Isner, one of the tour's most-powerful servers, had only three aces in the first set, while adding a double fault and 16 unforced errors. That allowed Berdych to break Isner's serve in the fifth game en route to winning the set.

However, Isner's serve and game improved in the second set. He had nine aces and pulled off a service break on Berdych in the opening game of the set.

"I was out of sorts," Isner said. "It was kind of a blustery day, and that caught me off guard a little. It was hard to get on top of the ball. I couldn't quite go for my shots. But that game (the first game of the second set) kind of got me going. I knew then that it was anybody's match."

Isner improved to 10-0 at Winston-Salem and continued his strong summer on hard courts. In addition to his wins at Newport and Winston-Salem, he made it to the quarterfinals at the London Olympics and the semifinals two weeks ago in Toronto.

Now, Isner — the highest-seeded American (ninth) in the U.S. Open — gets a few days off before his first-round match against Xavier Malisse of Belgium on Wednesday.

"I'm going in feeling pretty good about myself," Isner said. "Everything I do for the next three days is going to be geared toward that first-round match."