Serena Williams pulls out of Cincinnati Open CINCINNATI — World No. 1 Caroline Wozniacki's disappointing US Open preparations continued Wednesday as she crashed 6-4, 7-5 to 76th-ranked American teenager Christina McHale at the WTA tournament here. The 21-year-old Dane suffered a collapse similar to last week's defeat in Toronto, where she went out in the second round after letting a 5-1 lead slip in the second set. Wozniacki had only returned to action in Toronto after a month out with a painful shoulder. Meanwhile, America's Serena Williams withdrew from the tournament ahead of her second-round match due to a foot problem. Serena's withdrawal allowed Australian world No. 10 Samantha Stosur to advance to a third-round contest with Chinese world No. 5 Li Na. Roger Federer, playing in his final event before the US Open, surged into the third round of the ATP hardcourt tournament Tuesday by beating Juan Martin del Potro in straight sets. The Swiss star cruised past del Potro 6-3, 7-5 for his first win over the Argentine in their last three matches which included the 2009 US Open final. French Open champion Li Na also moved smoothly into the third round Tuesday with a straight-set 6-3, 6-4 victory over Lucie Safarova. Fourth-seeded Russian Maria Sharapova, sixth-seeded Wimbledon champion Petra Kvitova and eighth-seeded Marion Bartoli also swept past their opponents in second-round matches Tuesday. All of the top eight seeds, led on the women's side by Caroline Wozniacki and on the men's by Novak Djokovic, have first-round byes. Sharapova routed qualifier Anastasia Rodionova 6-1, 6-3, finishing off the Australian in just 71 minutes. Sharapova posted just one ace but dominated with her serve winning 57 percent of her second serves and converting six of seven break point chances. Sharapova will face the winner of a match between Russian Svetlana Kuznetsova and Czech Petra Cetkovska in the next round. In other first-round matches Tuesday, in-form former world No. 1 Serena Williams — winner of her last two tournaments — held on to beat tenacious Czech Lucie Hradecka 6-3, 7-6 (7/5). Unseeded Flavia Pennetta upset 12th-seeded Russian Anastasia Pavlyuchenkova 2-6, 6-3, 6-3, while 13th-seeded Jelena Jankovic of Serbia cruised past Czech Iveta Benesova 6-0, 6-3. On the men's side, Czech Radek Stepanek - winner of his first title in 2 1/2 years earlier this month when he won the Washington Classic - withstood 21 aces from John Isner to defeat the gargantuan American 7-5, 5-7, 7-6 (7/4). Jo-Wilfried Tsonga, a Wimbledon semifinalist and the 15th seed, defeated Croatia's Marin Cilic 6-3, 6-4, while Croatia's Ivan Dodig defeated Latvia's Ernests Gulbis 6-3, 7-6 (7/3) to line up a second-round clash with sixth-seeded Frenchman Gael Monfils.
