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, who rallied to beat Czech Lucie Hradecka 6-2, 6-7 (4), 6-3; and Latvia's Anastasija Sevastova, a 2-6, 6-2, 6-4 winner over Frenchwoman Alize Cornet.
Second-seeded Anastasia Pavlyuchenkova of Russia booked her quarterfinals berth Monday with a win over Melanie Oudin.