STANFORD, Calif. (AP)—Venus Williams advanced to the Bank of the West quarterfinals Thursday night, beating fourth-seeded Victoria Azarenka 6-4, 7-6 (1).
Williams, who reached her third quarterfinal of the season, will face eighth-seeded Andrea Petkovic on Friday.
Ana Ivanovic advanced to her first Bank of the West quarterfinal, beating qualifier Carol Zhao 6-1, 6-1 earlier on Thursday.
The 11th-ranked Serb, looking for her fourth title of the year, will face top-ranked Serena Williams on Friday.
Zhao, a sophomore All-American at Stanford, appeared in her second WTA Tour event and gained her first career win at the level Tuesday when Yanina Wickmeyer retired because of a viral infection.
Ivanovic, a former No. 1, had three aces and won 75 percent of her first-serve points.