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.
She is joined in the last eight by fellow Briton Heather Watson, who beat Slovenia's Polona Hercog 6-2 6-3.
Naomi Broady also won again, reaching round three of the Malaysian Open by beating China's Yang Zhaoxuan 6-4 6-3.
Konta, seeded fourth, goes on to face another Belgian in Kirsten Flipkens or Alison van Uytvanck, while Watson will meet either second seed Caroline Wozniacki or Mirjana Lucic-Baroni.