Roddick, who also won at Washington in 2001 and 2005, captured his 23rd career singles crown and second of the year at the 600,000-dollar tune up for the US Open, the year's final Grand Slam event that begins in three weeks.

"I was happy with the way I could control things with my serve," Roddick said. "I was putting pressure on him. I was making him serve well out of jams. I returned well. If I was putting a racket on it I was putting it on the court."

Wild card Isner missed out on a perfect ending to a week that saw him win five matches in a row in third-set tiebreakers, thought to be an unprecedented feat, after making the field only because wild card Fernando Gonzalez withdrew.

"The whole week has been a dream come true. It's amazing," Isner said. "I will always remember playing Andy Roddick in an ATP final. It's a big honour. I will never ever forget it. It's unbelievable."

Fifth-ranked Roddick took the 74,250-dollar top prize while 6-foot-9 Isner, who fired 144 aces and hit 70.4 percent of first serves this week, will jump to about 190th in the rankings and received a Cincinnati Masters wild card.

"With that serve, he is going to have a chance in every match he plays," Roddick said. "The guy is going to have a hard time not winning matches. It's going to be hard for him not to have a good career."

Isner, 22, surrendered a break at love in the seventh game of the first set, netting two backhands and a forehand before sending a forehand long. Roddick served out to the finish, ending the set with an ace.

"I knew it was a new experience for him. I wanted to put the pressure on early. I didn't want him to have an easy match," Roddick said.

"It's tough not to hit the ball right at him. He's everywhere at the net. I wasn't so much trying to pass him on the first ball as much as make him react."

Isner smacked the ball into the net on an easy overhead smash on the first point of the ninth game in the second set.

"I couldn't believe I could miss that shot but I did," Isner said. "Thank God I didn't lose that game and the match 4 and 4 after losing the easiest point in history."

Roddick, who fired 14 aces in the match, was impressed at how well Isner, who blasted 12 aces, handled the humiliation to hold serve.

"He kept his composure," Roddick said. "I thought he recovered pretty well."

In the tie-breaker, Isner sent a backhand long to give Roddick a 3-1 lead and the veteran rode it to the finish, which came on a forehand winner after 81 minutes.

"He kept me off-balance with his serve the whole week," Isner said. "I'm tired. I need a rest. I don't know how much I had left in the tank after five matches. But even with a full tank, I don't think so."

Roddick won his only prior title this year at Queen's in June. His only other final was in February at Memphis, where he lost to Tommy Haas.

Roddick, who turns 25 later this month, improved to 42-10 for the year with his 10th victory in a row at Washington, where he is 23-3 lifetime. Roddick missed defending his 2005 title last year due to an abdominal strain.

Isner, who would have been the third-lowest-ranked winner in ATP history, lost his ATP debut July 9 on grass at Newport and won a Challenger event last week in Lexington before his wonder run.

"It does wonders for my confidence," Isner said. "I feel like I can go out there and compete with anybody."