Maria Sharapova was pushed to three sets in the first round but eventually beat Ai Sugiyama.
Ai Sugiyama pushed her first round match against Maria Sharapova to three sets before falling.
Nine-time Grand Slam champions the Williams sisters won their first doubles match in two sets.
Li Na saved six match points but fell to Serena Williams in the first round, 63 76(6).
Venus Williams needed just over an hour to win her opener over StÃ©phanie Dubois, 62 63.
Marion Bartoli hydrated during a tight first round win over Japan's Ayumi Morita.
Nadia Petrova bounced her racquet during a 61 62 loss to countrywoman Maria Sharapova. Petrova was the No.5 seed.
Crafty Romanian Monica Niculescu lined up a forehand during her 61 75 second round loss to Samantha Stosur.
Alla Kudryavtseva had come close to beating Venus Williams before but this time fell to the world No.3, 61 75.
Marion Bartoli, seeded No.8 in Stanford, stopped the run of qualifier Melanie Oudin in the second round, 75 64.
World No.2 Serena Williams fell to Samantha Stosur in the quarterfinals, Stosur's equal-best career win.
Jelena Jankovic held two match points at 63 65 but wound up on the losing end to Marion Bartoli in the quarterfinals, 36 76(3) 63.
Maria Sharapova was impressive in reaching the quarterfinals but was stopped abruptly once there by Venus Williams, 62 62.
The silhouette of Marion Bartoli's serve was on court at dusk as she took on Jelena Jankovic in the quarters.
Samantha Stosur was on fire in the second set but lost her semifinal match to Marion Bartoli in three, 63 16 61.
The Williams sisters discussed strategy on the court en route to winning the doubles title on Sunday afternoon.
Marion Bartoli lined up a serve during the Bank of the West Classic singles final on a sunny Sunday afternoon.
Venus Williams powered a backhand during her singles final against Marion Bartoli in Stanford on Sunday.
Marion Bartoli threw her arms in the air after closing out a 62 57 64 victory over Venus Williams in the final of the Bank of the West Classic.
Marion Bartoli held up her fifth and biggest Sony Ericsson WTA Tour singles trophy at the Bank of the West Classic.