American Coco Gauff missed out on a place in the final of the Top Seed Open in Kentucky after a straight-set defeat by compatriot Jennifer Brady.
Brady, ranked four places higher than her 16-year-old rival at 49, used her big serve and power to good effect to win 6-2 6-4.
The 25-year-old will play Switzerland's Jil Teichmann in Sunday's final.
Teichmann, ranked 63 in the world, got the better of Serena Williams's conqueror Shelby Rogers 6-3 6-2.
Brady came into Saturday's semi-final having not lost a set and only dropping 11 games in the tournament.
She broke Gauff twice early on to open up a 4-1 advantage in the opening set and although Gauff recovered one of the breaks, Brady's heavy hitting kept her in control.
Brady broke again early in the second set and although Gauff briefly threatened a comeback, that was short-lived as Brady went on to reach her first final of 2020 having reached the last four in Dubai in February.