Zheng Jie knocks Venus Williams out of U.S. Open NEW YORK - Venus Williams and Zheng Jie played from the baseline and at the net. They played in the rain when every other match on the grounds of the Billie Jean King Tennis Center had been stopped. But finally Zheng, a 30-year-old from China, steadied her nerves and played a tiebreaker in which she took advantage of mistakes by Williams for a 6-3, 2-6, 7-6 (5) victory in a second-round match Wednesday in the U.S. Open. It is the third year in a row Williams has lost here in the second round and she gave every ounce of effort in her 33-year-old body that is touched by an immune system disease and pained by back issues. She lunged for volleys and yelled with effort on big serves, but Zheng kept her face emotionless and refused to let her game break down with nerves. "If I didn't think I had anything left in the tank I wouldn't be here," Williams said about when she might retire. I still think I do and that's why I'm still here. Zheng had words for the pro-Williams crowd. "I'm sorry," she said. Also still here, though not with ease, is 2009 U.S. Open champion and sixth-seeded Juan Martin del Potro of Argentina, who won a contentious first-round match against Guillermo Garcia-Lopez of Spain, 6-3, 6-7 (5), 6-4, 7-6 (7). The two exchanged heated words during the match and barely shook hands at the end. Defending champion and third-seeded Andy Murray won a straightforward first-rounder, defeating Michael Llodra of France, 6-2, 6-4, 6-3. Less routine was the way that popular 33-year-old American James Blake ended his career. Once ranked as high as No. 4 in the world, Blake lost to Croatia's Ivo Karlovic, 6-7 (2), 3-6, 6-4, 7-6 (2), 7-6 (2). Blake had already announced he would retire after losing here. Karlovic served 38 aces, but it was Blake who earned a standing ovation when he said, "I appreciate everything I did in my life. To do this in front of you guys, it will never be forgotten. His voice broke as he said, "I'll never forget you." This was Williams' 15th appearance at the U.S. Open and her 60th in a Grand Slam event, but the last of her two U.S. Open titles came in 2001. "I'm used to delays and what have you," Williams said. I definitely wish I was playing in the third round, but it's not to be for me this year. I tried. I just didn't play consistently enough. There had been four hours of rain delays during the day, including one that came when Zheng and Williams had each won a point. Venus' younger sister, top-seeded Serena, had her match postponed by the rain. This was only Williams' fourth match since the French Open. She missed Wimbledon because of her sore back and when she lost the first set it seemed this might be a quick loss. But Williams broke Zheng's serve in the first game of the second set when Zheng hit a forehand wide and Williams kept that advantage throughout the set. Zheng jumped ahead 3-0 in the final set over Williams, whose ranking had dropped to No. 60 in the world. Williams would not just walk away, though. She evened the set at 3-3 and now the crowd was on its feet. Zheng, ranked 56th in the world, won her serve for 4-3 and broke Williams to give herself a chance to serve out the match. She couldn't. As rain stopped matches on every other court, Zheng and Williams kept playing and Williams began hitting her ground strokes even harder and evened the set at 5-all. After the players sat through about a five-minute sprinkle, they each held serve to force the decisive tiebreaker that would belong to Zheng. Williams said her body can take more. "I've been dealt some cards that aren't as easy to deal with," she said, "but I have to play with them." Much earlier in the day, before the rain, third-seeded Agnieszka Radwanska and fifth-seeded Li Na had little trouble moving to the third round. Poland's Radwanska beat Silvia Soler-Espinosa of Spain, 6-0, 7-5 and China's Li eliminated Sofia Arvidsson of Sweden, 6-2, 6-2. Li, who has a new coach in Carlos Rodriguez, who used to work with Justine Henin, said she was pleased to have made her serve better with Rodriguez and also that she was finding the will to sometimes serve and volley.