Venus wins through, Wozniacki hurt
Venus Williams battled through in Stanford, while Caroline Wozniacki retired due to an injury.
Veteran Venus Williams fought her way into the Bank of the West Classic quarter-finals as Caroline Wozniacki succumbed to injury in Washington.
A two-time champion in Stanford, Williams overcame Magda Linette 6-3 6-7 (6-8) 6-2 at the WTA Premier event on Wednesday.
Williams needed two hours, 14 minutes to earn her second-round win.
Johanna Konta and Misaki Doi also advanced, while seventh seed Alize Cornet was beaten.
Konta thrashed Julia Boserup 6-3 6-1 and Doi won an all-Japanese affair against Nao Hibino 6-3 6-4.
But Cornet was no match for Zheng Saisai, suffering a 6-4 6-1 loss.
In Washington, Wozniacki led Samantha Stosur 7-5 3-4 when the Dane retired due to an elbow injury.
In other second-round matches, Yanina Wickmayer claimed a 6-3 7-5 win over Zhang Shuai and wildcard Jessica Pegula beat Christina McHale 7-5 6-2.
Kristina Mladenovic completed her opener against Samantha Crawford, winning 6-2 2-6 6-3.
Lauren Davis was pushed far more before registering a 5-7 7-5 6-3 victory over Shelby Rogers, while Yulia Putintseva edged past American teenager Usue Maitane Arconada 6-4 4-6 6-4.