Advancing were defending champion Nicole Gibbs and freshman Krista Hardebeck of Stanford and sophomore Zsofi Susanyi of Cal.
All three are scheduled to play today at 9 a.m. PDT. All singles and doubles matches will be streamed live at www.ncaa.com.
Gibbs, a junior from Santa Monica, is trying to become the first woman since Stanford's Amber Liu in 2003-04 to win consecutive NCAA singles titles. Liu is married to International Tennis Hall of Famer Michael Chang.
Gibbs, seeded 9-16, will face fourth-seeded Cristina Sanchez-Quintanar of Texas A&M for the second time in four days. Gibbs won 0-6, 6-2, 6-0 at No. 1 singles in the Cardinal's 4-3 victory over the Aggies on Tuesday in the NCAA team final.
Fifth-seeded Zsofi Susanyi of Cal dismissed Lucia Batta of UNLV 6-3, 6-4 in an all-Hungarian matchup. Susani, a semifinalist last year, will take on 9-16 seed Yana Koroleva of Clemson. Meanwhile, Cal freshman Klara Fabikova and Santa Clara junior Katie Le lost. So did all three doubles teams from Northern California schools, two women's and two men's, in the first round.
Most notably, 5-8 seeds Kristie Ahn and Gibbs fell to Isaura Enrique and Samantha Vickers of Tulsa 6-2, 6-4. Therefore, Stanford's streak of three consecutive women's doubles champions will end. Gibbs won last year's crown with Mallory Burdette, who turned pro last September after her junior year.
Also losing on Thursday were Cal's Campbell Johnson and Christoffer Konigsfeldt, the Men's Doubles Team of the Year in the Pacific-12 Conference.
Zsofi Susanyi (5), Cal, def. Lucia Batta, UNLV, 6-3, 6-4.
Krista Hardebeck (9-16), Stanford, def. Cindy Chala, Virginia Commonwealth, 1-6, 7-5, 6-4.
Mary Weatherholt (9-16), Nebraska, def. Klara Fabikova, Cal, 6-2, 6-1.
Robin Anderson (3), UCLA, def. Katie Le, Santa Clara, 7-6 (1), 6-2.
Lauren Embree and Sophie Oyen, Florida, def. Stacey Tan and Ellen Tsay, Stanford, 6-3, 2-6, 6-4.