Top seed Samantha Stosur and former world No. 1 Ana Ivanovic secured quarterfinal berths at the Kremlin Cup tennis event.
The Aussie veteran Stosur held off France's Alize Cornet 7-6 (8-6), 7-5, while the fourth-seeded Serbian Ivanovic cruised past Russian qualifier Valeria Solovieva 6-1, 6-4 Thursday on the indoor hardcourts at Olympic Stadium.
Meanwhile, seventh-seeded Russian favorite Maria Kirilenko topped Kazakhstan's Yaroslava Shvedova 7-5, 6-4. The Moscow native Kirilenko was a hometown runner-up two years ago.
Also on Day 4, Serbian qualifier Vesna Dolonc whipped Romanian Simona Halep 6-1, 6-0.
Friday's quarterfinals will pit Stosur against Czech Klara Zakopalova; third- seeded former No. 1 Caroline Wozniacki of Denmark versus fifth-seeded reigning Moscow titlist Dominika Cibulkova of Slovakia; Ivanovic against Dolonc; and Kirilenko versus Swede Sofia Arvidsson.
Cibulkova beat Estonian Kaia Kanepi in last year's Moscow finale.
The 2012 winner of this $740,000 tournament will collect $122,000.