Tianjin - Varvara Lepchenko and Alison Riske have set up an all-American quarter-final 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.