(CNN) -- Juan Martin Del Potro edged top seed Andy Roddick to successfully defend his Legg Mason Classic title in Washington with a 3-6 7-5 7-6 victory in Sunday's final.
Del Potro served brilliantly in the deciding tie-breaker to retain his Legg Mason title in Washington.
The Argentine produced five aces in the deciding tiebreaker which he took on his fourth match-point when the Hawk-Eye review system upheld a forehand winner.
"I did my best services ever in my life," Del Potro told the official ATP Tour Web site www.atpworldtour.com after making 19 aces in the grueling two and a half hour match.
Sweltering and humid conditions made it difficult for both players and Del Potro admitted it had been tough.
"After the first set I couldn't move any more. It was impossible. It was serve and one more ball. If you run, you die."
Roddick, playing his first tournament since his five-set defeat to Roger Federer in the Wimbledon final also believed conditions proved a factor.
The three-time tournament winner in Washington had been afforded the honor of playing night matches all week and found the afternoon heat stifling.
To be honest, it hasn't been a typical Washington summer, he said.
"Today was brutal. To play (at 2:30) was tough. Credit to him for winning. The guy has been a solid top five player for over a year now."
Roddick went a set up with a single break of service in the opener, but was broken twice in the second set as the second seed leveled.
Del Potro fell behind to an early break in the decider, but Roddick double faulted on break point to even the set at three-all.
Del Potro opened the tie-breaker with an ace and three more gave him a 6-3 lead. Roddick, who had never been beaten in a Washington final, bravely saved three match points, but his marginally long forehand proved his undoing.
Argentine Del Potro is the first player since Andre Agassi in 1999 to win back-to-back titles at the American hardcourt tournament.