American Amanda Anisimova, the No 8 seed, moved into the last eight of the Charleston Open by beating Kazakh Yulia Putintseva, the No 10 seed, 6-4, 6-4 at the Family Circle Tennis Center on Thursday.
Anisimova, ranked No 16, will face the winner of the match between No 15 seed Ashlyn Krueger and No 4 seed Emma Navarro next.
The American won against Russian Veronika Kudermetova (6-2, 6-2) in the previous round of the Charleston tournament.
In the second round of the Charleston tournament, Putintseva, ranked No 23, defeated Chinese qualifier Shuai Zhang (7-6 (5), 6-1).
Charleston WTA 500, other last 16 results (Family Circle Tennis Center, clay, USD 1.064.510, most recent results first):
- Daria Kasatkina vs. Sofia Kenin
- Anna Kalinskaya vs. Madison Keys
- Qinwen Zheng vs. Elise Mertens
- Jessica Pegula vs. Ajla Tomljanovic
- Jelena Ostapenko vs. Danielle Collins
- Ashlyn Krueger vs. Emma Navarro
- Ekaterina Alexandrova vs. Diana Shnaider: thursday
