TIANJIN, China (AP) — Varvara Lepchenko and Alison Riske set up an all-American quarterfinal match at the Tianjin Open with straight-set wins on Wednesday.

The fourth-seeded Lepchenko defeated 18-year-old Chinese wild-card entry Liu Fangzhou 7-6 (3), 7-5, while the sixth-seeded Riske beat Olga Govortsova of Belarus 6-4, 7-6 (3).

Also, Sorana Cirstea of Romania beat Andrea Hlavackova of the Czech Republic 6-3, 6-0, and Ajla Tomljanovic of Croatia defeated Tianjin native Duan Ying-ying 6-4, 6-4.

Jelena Jankovic is the top-seeded player at the tournament, one of three events added to the WTA Tour calendar in China this year. She plays her second-round match against Zheng Saisai on Thursday.

Copyright 2014 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.