Top-seeded Jelena Jankovic of Serbia downed Austria's Sybill Bammer 6-3, 6-4 to reach the quarterfinals of the Monterrey Open on Thursday.
Jankovic saved eight break points before closing out the win in just under 90 minutes.
Joining the No. 6 ranked Jankovic was Argentina's Gisela Dulko, who cruised past Aleksandra Wozniak of Canada, 6-4, 6-1. Ksenia Pervak of Russia rallied to beat Czech Lucie Hradecka 6-2, 6-7 (4), 6-3, and Latvia's Anastasija Sevastova beat Frenchwoman Alize Cornet 2-6, 6-2, 6-4.
Second-seeded Anastasia Pavlyuchenkova of Russia booked her quarterfinals berth on Monday with a win over Melanie Oudin.