New York, Sep 15 (DPA) Juan Del Potro upset Roger Federer 3-6, 7-6 (7-5), 4-6, 7-6 (7-5), 6-2 to win the US Open title Monday and fulfill a career dream at age 20.

The sixth seeded Argentine rode an early break in the final set to keep the top seed at bay. Federer saved two match points in the final game before Del Potro drove home the win.

He becomes the first Argentine since Guillermo Vilas to win the New York title. Federer was thwarted in his bid to become the first man in modern history to win six straight trophies at the same event.