Maria Sharapova beats Nadia Petrova to reach U.S. Open quarterfinals . The Russian will play former world Marion Bartoli wins 12 of 13 games to secure 1-6 , 6-2 , 6-0 win over Petra Kvitova . Sam Stosur ends 18-year-old Laura Robson 's impressive U.S. Open run with a 6-4 6-4 win .
Maria Sharapova beats Nadia Petrova to reach U.S. Open quarterfinals . Sharapova has won 11 three-set matches in 2012 . Marion Bartoli wins 12 of 13 games to secure 1-6 , 6-2 , 6-0 win over Petra Kvitova . Sam Stosur ends 18-year-old Laura Robson 's impressive U.S. Open run with a 6-4 6-4 win .