Which Argentine defeated Roger Federer in the 2009 US Open men's singles final?

Juan Martín del Potro defeated Roger Federer in the 2009 US Open men's singles final.

The Argentine won a dramatic five-set match, 3–6, 7–6, 4–6, 7–6, 6–2, overcoming the defending champion after falling behind twice in sets. The victory gave del Potro his first major singles title and ended Federer's run of five consecutive US Open championships.

At 20 years old, del Potro became the first Argentine to win the US Open since Guillermo Vilas in 1977. He was also the first South American man to win a Grand Slam singles title on a hard court. The match was the first US Open men's final since 1999 to go to five sets.

The result is sometimes mixed up with other Argentine tennis stars. David Nalbandian and Guillermo Coria reached major prominence but did not win this US Open final, while Diego Schwartzman never reached a Grand Slam singles final. Del Potro's 2009 triumph remains his only major singles championship.