Top seed Jelena Jankovic is through to the last eight of the WTA Monterrey Open after defeating Sybille Bammer on Thursday.
Serbian Jankovic, ranked sixth in the world to Bammer's 107th, won 6-3 6-4 in one hour and 29 minutes at the Sierra Madre Tennis Club.
Jankovic broke the Austrian four times while only giving up her own serve twice to book a quarter-final against Latvian Anastasija Sevastova.
Fifth-seed Sevastova needed three sets to progress from her second-round tie against Frenchwoman Alize Cornet.
Cornet claimed the first set, but Sevastova, 29 places above her opponent at 38 in the world, rallied to win through 2-6 6-2 6-4 in two hours and two minutes.
In other second-round matches, Argentine Gisela Dulko made short work of Canada's Aleksandra Wozniacki.
World No.56 Dulko breezed past the qualifier 6-4 6-1 in one hour and 14 minutes to set up a quarter-final with Russian Ksenia Pervak.
Pervak, 19, needed three sets to overcome Czech qualifier Lucie Hradecka 6-2 6-7 (4-7) 6-3.
It was Pervak's first career victory over the 25-year-old in four meetings.