Vera Zvonareva and Sam Stosur became the sixth and seventh players to qualify for the WTA Championships in Istanbul, October 25-30.  With her three-set victory over Andrea Petkovic in the final of the China Open, Agnieszka Radwanska took over the eighth and final spot from Marion Bartoli. The tournament in Linz announced that Petkovic had pulled out with knee injury, so the German can no longer qualify for the Championships. According to the WTA, France’s Bartoli has to win both Osaka and Moscow and hope that Radwanska doesn’t reach the quarterfinals of Moscow to grab the last spot form the Pole. No. 1 Caroline Wozniacki, Maria Sharapova, Petra Kvitova, Victoria Azarenka, and Li Na have already qualified.