Fresh off her fifth Wimbledon title, Serena Williams eased past wild card Nicole Gibbs on Wednesday at the $740,000 Bank of the West Classic.

The former top-ranked star and reigning Stanford champion needed just 62 minutes to knock off the 19-year-old Gibbs 6-2, 6-1 on the hardcourts at Stanford's Taube Family Tennis Stadium.

Williams beat Marion Bartoli, this week's No. 2 seed, in last year's Stanford final. Bartoli, who won the event in 2009 and was also a runner-up in 2008, will play her second-rounder on Thursday.

Coco Vandeweghe upset former world No. 1 and fourth-seeded Serb Jelena Jankovic 6-4, 6-2. The 20-year-old American was 5-of-9 in break-point opportunities.

Fifth-seeded Yanina Wickmayer and sixth-seeded Chanelle Scheepers were also winners on Wednesday. Wickmayer bounced back from a first set loss to beat Heather Watson, 5-7, 6-1, 6-4 and Scheepers took care of wild card Michelle Larcher de Brito, 6-3, 6-4.