Britain's Johanna Konta won a hard-hitting contest against Slovakian Dominika Cibulkova to reach the Cincinnati Open quarter-finals.
The seventh seed won 6-3 6-4 to reach the last eight for the first time, setting up a rematch of her Wimbledon quarter-final against Simona Halep.
Romanian second seed Halep beat Latvian 15th seed Anastasija Sevastova 6-4 6-3.
In the men's event, top seed Rafael Nadal will play fellow Spaniard Albert Ramos-Vinolas later on Thursday.
Bulgarian seventh seed Grigor Dimitrov beat Argentine Juan Martin del Potro for the first time in six attempts, coming through 6-3 7-5.