STANFORD, California (AP) American teenager Madison Keys beat No. 8 seed Magalena Rybarikova 6-2, 6-2, in the first round of the Bank of the West Classic on Monday.
Keys won 70 percent of her first serve points and beat Rybarikova for the second time in three matches.
Sorana Cirstea, the only other seeded player appearing on opening day, beat Ayumi Morita 6-2, 6-2.
Cirstea, seeded fifth, played a clean match with few unforced errors and no double faults.
In other first-round matches, Belarus' Govortsova downed Germany's Julia Goerges, 7-6 (2), 6-2; Italian Francesca Schiavone topped American Mallory Burdette 7-5, 6-3; and Sweden's Stefanie Voegele bettered wild card Ajla Tomljanovic of Croatia 6-4, 6-0.