British number one Johanna Konta suffered a shock straight-set defeat by 18-year-old Marketa Vondrousova in the second round at Indian Wells.
World number 11 Konta had four set points in the first set and led 4-2 in the second but lost 7-6 (7-5) 6-4 to her 54th-ranked Czech opponent.
Wimbledon champion Garbine Muguruza was also knocked out in three sets by USA’s world number 100 Sachia Vickery.
Konta has won just eight matches since her 2017 Wimbledon semi-final.
The 26-year-old, who had a bye into the second round in California, said it was "one of the toughest losses I’ve had."