Coco Gauff was dumped out of the Madrid Open on Monday by American compatriot Madison Keys in the last 16, losing 7-6 (7/4), 4-6, 6-4.
The world number three, who has not reached a WTA final on clay since losing the 2022 French Open showpiece to Iga Swiatek, led 4-2 in the deciding set but Keys won four straight games to secure victory.
Keys' reward for defeating US Open champion Gauff is a quarter-final against Tunisian eighth seed Ons Jabeur.
