Day 4 of the 2012 U.S. Open was a full day of action highlighted by a major upset in the men's singles bracket. No. 5- seeded Jo-Wilfried Tsonga was beaten in four sets by unranked Martin Klizan 6-4, 1-6, 6-1, 6-3. The other big news from the day was the announcement that Andy Roddick will be retiring. The No. 22 player in the world announced on his 30th birthday that no matter the outcome, this would be his last tournament. As he explained to USOpen.org:
"I just feel like it’s time. I don’t know that I’m healthy enough or committed enough to go another year. I’ve always wanted to, in a perfect world, finish at this event (the US Open). I’ve thought all year that I would know when I got to this tournament. When I was playing my first round, I knew."
No. 1-seeded Roger Federer fared better than Tsonga, taking out Bjorn Phau in three straight sets 6-2, 6-3, 6-2. In the women's singles draw, No. 4-seeded Serena Williams advanced into Round 3 with a win over Maria Jose Martinez Sanchez.