Wimbledon champion Muguruza wins in 1st match back

STANFORD, Calif. (AP) Wimbledon champion Garbine Muguruza beat Kayla Day 6-2, 6-0 to reach the Bank of the West Classic quarterfinals on Wednesday, easily advancing from her first competitive match since beating Venus Williams in the final at the All England Club last month.

The top-seeded Muguruza overwhelmed the 17-year-old American in less than an hour.

''Kayla has just won the US Open in juniors and she's just very promising, so I knew I had to be concentrated today,'' Muguruza said.

The Spaniard will next No. 5-seeded Ana Konjuh, a 7-5, 6-5 winner over Russia's Natalia Vikhlyantseva.

Five-time major winner Maria Sharapova withdrew from her scheduled match because of soreness in her left arm. Seventh-seeded Lesia Tsurenko moved on to face Madison Keys.

The third-seeded Keys rallied past qualifier Caroline Dolehide 3-6, 6-2, 6-3 in an all-American match. Keys won four straight games in the second set and made an early break in the third.