Williams sisters out, Clijsters advances

CINCINNATI, Aug. 13 (UPI) -- Flavia Pennetta and Sybille Bammer pulled off huge upsets Thursday, eliminating the Williams sisters in the third round of the Western & Southern Women's Open.

Top-seeded Dinara Safina, meanwhile, reached the quarterfinals along with former world No. 1 Kim Clijsters in her return to competitive tennis.

Pennetta defeated Venus Williams 7-6 (7-2) 6-4 at the Lindner Family Tennis Center and Bammer pulled off an even bigger stunner with a 7-5, 6-4 win over Serena Williams.

Serena Williams has won 11 major titles and is the current Wimbledon, Australian Open and U.S. Open champion. Bammer has appeared in 16 major events and has made it as far as the quarterfinals in only one of them -- last year's U.S. Open.

Pennetta is coming off her second tour victory last week in Los Angeles.

Safina made it to the quarterfinals with a 6-3, 6-4 triumph over Peng Shuai, setting up a matchup with Clijsters.

Clijsters, coming back from a two-year retirement, surprised Svetlana Kuznetsova 6-4, 4-6, 6-2.

Elena Dementieva advanced with a 6-4, 6-4 win over Sorana Cirstea, Jelena Jankovic defeated Victoria Azarenka 7-5, 7-6 (7-4) and Daniela Hantuchova eliminated Vera Zvonareva 7-6 (8-6), 0-6, 7-6 (7-5).

Pennetta will face Hantuchova in the quarterfinals, Jankovic will meet Bammer and Dementieva will take on Caroline Wozniacki.

Wozniacki reached the quarterfinals when Melinda Czink retired in the first set with a lower back injury.