Fifth-seeded Yanina Wickmayer and sixth- seeded Chanelle Scheepers both posted first-round victories Monday at the $740,000 Bank of the West Classic tennis event.

The Belgian Wickmayer snuck past Taipei's Kai-Chen Chang 7-5, 2-6, 7-5 on the hardcourts at Stanford's Taube Family Tennis Stadium.

Scheepers eased past American Grace Min in straight sets with a 6-4, 6-4 decision. The South African converted on 6-of-9 break chances to overcome five double faults.

Portugal's Maria Larcher De Brito shook off a first-set loss to down Slovakian Jarmila Gajdosova by a 5-7, 6-2, 6-3 count.

This week's top seed is Wimbledon champion Serena Williams, who beat Marion Bartoli, this week's second seed, in last year's Stanford finale. Bartoli titled here in 2009 and was also a runner-up in 2008.