STANFORD, Calif. (AP) Top-seeded Garbine Muguruza rolled past Croatia's Ana Konjuh 6-1, 6-3 in just over an hour on Friday to reach the semifinals of the Bank of the West Classic.
The reigning Wimbledon champion broke Konjuh's serve twice for an early 3-0 lead and never trailed in the match.
''I think today I was very accurate. Ana is such a powerful player and super young, I knew I had to be concentrated,'' Muguruza said. ''I'm super happy that I'm ... through to the semifinals, and I'm pretty happy with the match.''
Muguruza will play third-seeded American Madison Keys, a 6-4, 6-3 winner over Lesia Tsurenko. Keys had 19 winners and five aces.
American's Catherine Bellis and Coco Vandeweghe each upset a seeded opponent. Bellis beat No. 2 Petra Kvitova 6-2, 6-0 for her first WTA premier semifinal and Vandeweghe knocked out No. 4 Anastasia Pavlyuchenkova 6-2, 6-3.