British number one Johanna Konta saw off Belgium's Yanina Wickmayer in two hard-fought sets to reach the quarter-finals of the Monterrey Open in Mexico.
Konta, ranked 21 places higher at 27 in the world, won 7-6 (8-6) 7-6 (7-4) after two hours and four minutes.
The Briton is through to her second quarter-final of 2016, having reached the last four at the Australian Open.
Fourth seed Konta goes on to face another Belgian in Kirsten Flipkens or Alison van Uytvanck.
British number two Heather Watson takes on Slovenia's Polona Hercog later on Wednesday.