Top seeds tumble in Toronto

12-08-2011

Serena WIlliams celebrates winning a point against Zheng Jie. Photo: Reuters.

Tennis: Vera Zvonareva, Maria Sharapova, Petra Kvitova and Li Na all made third-round exits at the Toronto Cup, in Canada. Third-seed Zvonareva was the highest-ranked casualty when she went down 6-4 7-6 to the number 13 seed, Agnieszka Radwanska.

Reigning Wimbledon champion Petra Kvitova was beaten 6-1, 6-2 by German 11th seed Andrea Petkovic. French Open champion Li - seeded sixth - also bowed out in straight sets to Australian 10th seed Samantha Stosur.

But Fifth-seed Sharapova provided the biggest upset when she waswhen she was ousted 6-3 7-5 by unheralded Kazakh Galina Voskoboeva.

Another Chinese player, Zheng Jie, lost 4-6 6-3 6-3 to former world number one Serena Williams, who's showing ever-improving form ahead of the US Open.