Serena struggles through

Serena Williams joined her Wimbledon conqueror Maria Sharapova in the quarterfinals of the China Open with a hard-earned 6-4, 3-6, 6-3 win over Russian Dinara Safin.

The top-seeded American struggled in the middle of her match against Safina, sister of men's champion Marat Safin, and was not pleased with her performance.

"Out of a 10, I think I give myself a one," she said. "She was hitting balls really hard right on the lines. It was really difficult for me to hit those back."

But she said she loved being in Beijing. "I already called my sister, Venus, and I said we are going to have so much fun here during the Olympics in 2008."

There were also second round wins for Gisela Dulko, of Argentina, and Spain's Anabel Medina Garrigues.