Argentina's Juan Martin del Potro has beat defending champion Roger Federer to win the US Open.
Del Potro battled back to beat the Swiss five-times champion 3-6 7-6 4-6 7-6 6-2 in a match lasting four hours and six minutes on Tuesday.
The 20-year-old Argentine become the first South American to win the New York title since his compatriot Guillermo Vilas in 1977.
Del Potro overcame some early jitters and a first set that saw him struggle with his first serves and heavy forehand in breezy conditions at the National Tennis Center.
But as the match wore on, the young Argentine gained confidence, winning the second-set tiebreaker 7-5, and after double-faulting the last two points to lose the third set, battled the world number one to another tiebreaker.
The Argentine won that decider by 7-4 to set up the first Open five-set final since Andre Agassi topped fellow-American Todd Martin 10 years ago.
Taking advantage of Federer's faulty serve, Del Potro broke the defending champion in the second game of the fifth set and cemented his advantage by breaking him again in the final game.
The win denied Federer a sixth successive title, that would have matched American Bill Tilden's achievement in the 1920s.
"You can't have them all," he said. "I've had an amazing summer and a great run."
