Top seed Jelena Jankovic eased into the semi-finals of the Monterrey Open after a comfortable win over fifth-seeded Anastasija Sevastova.
The Serbian raced to the first set before being forced to dig deeper to see off her Latvian opponent in the second, eventually prevailing 6-1 7-5.
Jankovic’s next opponent will be Polona Hercog, the eighth seed from Slovenia, who defeated Olga Govortsova of Belarus 4-6 6-3 6-3.
Second seed and defending champion Anastasia Pavlyuchenkova of Russia booked her place in the last four with a 6-2 7-6 (7/3) victory over Hungary’s Greta Arn.
Pavlyuchenkova opponent in the semi-finals will be Argentina’s Gisela Dulko, who crushed Russia’s Ksenia Pervak 6-1 6-0.