British number one Johanna Konta advanced to the quarter-finals of the Monterrey Open with a 7-6 (7-4) 6-3 win over Germany's Tatjana Maria.
World number 91 Maria had beaten Britain's Heather Watson in three sets in the previous round.
But in her first meeting with the 32-year-old, second seed Konta sealed victory in one hour 47 minutes.
Konta, 28, will play Russian 18-year-old Anastasia Potapova in the last eight on Friday.
Meanwhile in the Challenger Series event in Indian Wells, Britain's Katie Boulter lost 6-3 6-3 to Ukraine's Lesia Tsurenko in the last 16.