British number one Johanna Konta was beaten in straight sets by Czech Republic's Marie Bouzkova in the semi-finals of the Monterrey Open.
Konta, the tournament's second seed, had progressed to the last four in Mexico on the back of her first victories of 2020.
Bouzkova, a former junior US Open champion, has risen up the rankings to 57 - and the 21-year-old secured a crucial break in the sixth game as she went on to claim the opening set.
World number 16 Konta, carrying a knee problem which required some strapping, had managed to hold two key service games before another costly unforced error saw the Briton broken again.
Bouzkova then saved a couple of break points on her next serve to close out victory, winning 6-3 6-4 in one hour and 41 minutes, to reach a first final on the main WTA Tour.