NEWPORT BEACH, CA, USA - In-form Canadian Bianca Andreescu started her third tournament of 2019 with another victory.

The No.6 seed defeated American qualifier Katie Volynets, 6-2, 7-6(7), in the second round of the Oracle Challenger Series event in Newport Beach on Wednesday, as one of six seeded players to advance on the second day of play.

Joining Andreescu in the third round was ttop seed Rebecca Peterson, No.5 seed Taylor Townsend, No.12 seed Nicole Gibbs, No. 14 seed Claire Liu and No.16 seed Jil Teichmann. 

Related: Bouchard rallies to advance at Newport Beach 125K

Andreescu's compatriot Katerine Sebov authored a notable upset on Wednesday, however, as she defeated defending champion and No.8 seed Sofya Zhuk in straight sets, 6-2, 6-2.

Zhuk was one of four seeds to fall on Wednesday, as American Allie Kiick and Lauren Davis defeated Yanina Wickmayer and Varvara Lepchenko, respectively, and Mexico's Renata Zarazua defeated No.4 seed Madison Brengle in three sets.

The event is the final stop in this year's Oracle Challenger Series, which also consists of WTA 125 events in Chicago and Houston last year. 

The top two American women’s and men’s points-getters over the course of the Series receive wildcards into their respective singles main draws at the BNP Paribas Open in Indian Wells.