Unranked Martin Klizan shocked fifth-seeded Jo-Wilfried Tsonga on Thursday, defeating him in Round 2 of the 2012 U.S. Open. Klizan won in four sets, 6-4, 1-6, 6-1 and 6-3. Also making news at the tennis tournament was Andy Roddick, who announced his retirement following the 2012 U.S. Open. "I just feel like it’s time," Roddick told USOpen.org. "I don’t know that I’m healthy enough or committed enough to go another year."
Top-ranked Roger Federer was in fine form, easily getting past Bjorn Phau. San Francisco-born Sam Querrey also advanced, moving into Round 3 with a win over Ruben Ramirez Hidalgo. In the women's singles draw, No. 4 seed Serena Williams defeated Maria Jose Martinez Sanchez.
For a complete list of the day's results, be sure to check out SI.com.