Jo-Wilfried Tsonga has been upset in the second round of the 2012 U.S. Open by Martin Klizan, 6-4, 1-6, 6-1, 6-3, marking the first major upset in this year's tournament. The No. 5 seeded Tsonga was dominated by the Slovakian. It is the first time in Tsonga's career that he has lost in the second round of the Open.

For Klizan, the No. 52 ranked player in the world, this likely marks the biggest win in his career. He will play the winner of the match between Jeremy Chardy and Matthew Ebden in the third round.

For a complete list of results, be sure to check out USOpen.org. Catch a live stream of many of the matches with U.S. Open Live.

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