STANFORD, Calif. (AP) Alison Riske and 17-year old wildcard CiCi Bellis each upset a ranked opponent on Tuesday in the first round of the Bank of the West Classic.

Bellis was down 4-1 in the second set but rallied to beat sixth-seeded Jelena Ostapenko 6-4, 6-4. It was the first Women's Tennis Association win of the year for Bellis.

Riske came back after losing the first set by four games to defeat No. 8 seed Varvara Lepchenko 2-6, 6-3, 7-6 (4). Riske won five straight games in the second set and the first three points of the third-set tiebreaker. Lepchenko was a BOTW semifinalist the past two years.

Julia Boserup, Urszula Radwanska and Magda Linette won afternoon matches and each will face an opponent with a first-round bye. Boserup and Linette both rallied after losing their first sets 6-2. Boserup, a wildcard, plays No. 3 seed Johanna Konta, Radwanska goes against second-seeded Dominika Cibulkova and Linette faces top-seed Venus Williams.