Serena Williams headlines Friday's four quarterfinal matches taking place at the Bank of the West Classic at Stanford University. The reigning Wimbledon champion takes on Chanelle Scheepers  of South Africa in Friday's fourth and final match.
Scheepers has just one WTA title under her belt and is the huge underdog against Williams. Friday's match against Williams will be Scheepers' first Premier-level quarterfinal.
Here are the other three matches scheduled for Friday:
- Urszula Radwanska (Poland) vs. Coco Vandeweghe (USA)
- Yanina Wickmayer (Belgium)  vs Marion Bartoli (France) 
- Dominika Cibulkova (Czechoslovakia)  or [Q] Erika SEMA (Japan) vs Sorana Cirstea(Romania) 
- Serena Williams (USA)  vs Chanelle Scheepers (South Africa)