Juan Martin del Potro, 20 gave one of the biggest surprises in the U.S. Open history beating Roger Federer, 28 the world's No.1 player at the U.S. Open 2009 men's singles final in a four-hour match 3-6, 6-7(5), 4-6, 7-6(4), 6-2 Monday evening at the Arthur Ashe Stadium in New York.

Del Potro overcame a 2 set deficit, taking out the five time U.S. Open champion. This was his first Grand Slam final.

I want to thank my team because without them it wouldn't be possible. To all the Argentines who are here and especially to my father, my mother, Julieta and all my friends and to the people who supported me all the time, this is for you, Del Potro said in Spanish just before receiving the championship cup. 

Watch Photos of the final match below:

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Juan Martin del Potro of Argentina reacts after defeating Roger Federer of Switzerland in their men's singles final match at the U.S. Open tennis championship in New York, September 14, 2009. REUTERS/Shaun Best
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Roger Federer of Switzerland hits a return to Juan Martin del Potro of Argentina in the men's singles finals at the U.S. Open tennis championship in New York, September 14, 2009. REUTERS/Kevin Lamarque
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Juan Martin del Potro of Argentina celebrates a point over Roger Federer of Switzerland in their men's singles finals match at the U.S. Open tennis championship in New York, September 14, 2009. REUTERS/Kevin Lamarque

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Roger

Roger Federer of Switzerland hits a return to Juan Martin del Potro of Argentina in their men's singles finals match at the U.S. Open tennis tournament in New York, September 14, 2009. REUTERS/Shaun Best
Juan

Juan Martin del Potro of Argentina hits a return to Roger Federer of Switzerland during their men's singles final match at the U.S. Open tennis tournament in New York, September 14, 2009. REUTERS/Shaun Best
Roger

Roger Federer of Switzerland reacts to breaking serve over Juan Martin del Potro of Argentina in their men's singles final match at the U.S. Open tennis tournament in New York, September 14, 2009. REUTERS/Kevin Lamarque
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Juan Martin del Potro of Argentina celebrates a point during the second set in his game against Roger Federer of Switzerland in their men's singles finals match at the U.S. Open tennis championship in New York, September 14, 2009. REUTERS/David Gray