British No 1 Johanna Konta is out of the Silicon Valley Classic after losing to Elise Mertens in the quarter-finals in San Jose.
It had been a promising week for Konta, who easily beat the great Serena Williams earlier in the tournament, but she could not find her way past the fourth seed on Friday.
Mertens has been in consistent form this year and the Belgian won 7-6 6-3 to set up a semi-final against Mihaela Buzarnescu.
The players had a break of serve apiece in the first set, before Mertens took the tie break 7-4.
And Mertens then broke twice in set two as she wrapped up victory in just over an hour and a half.