Juan Martín del Potro defeated five-time defending champion Roger Federer in the final, 3–6, 7–6, 4–6, 7–6, 6–2 to win the men's singles tennis title at the 2009 US Open. It was his first and only major title. Del Potro was the first Argentine to win the title since Guillermo Vilas in 1977. This was the first US Open final since 1999 to go to five sets. From Wikipedia
