Williams wins through to semifinals

World number three Venus Williams faces a possible walkover in Friday's Australian women's hardcourt championships semifinals after a straight sets victory in Thursday's quarter-finals.

The American's scheduled opponent, Russia's world number 39 Nadia Petrova, overcame a shoulder injury to beat fifth-seeded Italian and world number 14 Silvia Farina-Elia 7-6 (7-4) 7-5 in their quarter-final on Thursday.

Petrova battled on bravely after dropping the first three games of the second set and receiving court-side treatment on her injured right shoulder.

Top seed Williams beat Japan's eighth seed Ai Sugiyama 6-2 6-4.

"I remember my first service game in the second set, I went through pain," Petrova said. "I saw my coach giving me the signal to just finish it up. I'm just a fighter and I thought: 'No way, I'm not going to give it up'.

"I told myself 'No matter what happens, I am just going to the end'. Maybe I won't play at all tomorrow. But I don't think it is that bad."

Seventh-seeded Czech Daja Bedanova beat Slovenia's Tina Pisnik 6-1 3-0 after Pisnik retired with a thigh muscle strain.

Second seed and defending champion Belgian Justine Henin, the world number seven, overpowered German Anca Barna 6-2 6-1.

Williams, 21, the U.S. Open and Wimbledon champion, arrived in Australia last week as part of her preparations for the Australian Open starting on January 14 in Melbourne.