British qualifier Harriet Dart lost in straight sets to American Madison Keys in the fourth round at Indian Wells.
Australian Open semi-finalist Keys won 6-1 6-4 against Dart, who is ranked 122 in the world, in California.
Dart, 25, is on course to break into the world’s top 100 for the first time following her run to the last 16.
Keys will face Iga Swiatek in the quarter-finals, after the Polish third seed came from a set down to defeat Germany’s Angelique Kerber 4-6 6-2 6-3.
Dart missed a break point in the opening game of the contest and that proved to be her only opportunity as 25th seed Keys ran away with the opening set.
The Briton survived break points in the first and fifth games as she sought to force a deciding set – but Keys, 27, broke to love for 5-4 before serving out the match.
Also in the women’s draw on Tuesday, Romanian two-time Grand Slam champion Simona Halep beat compatriot Sorana Cirstea in straight sets, winning 6-1 6-4.
Halep will meet Petra Martic – who knocked out British number one Emma Raducanu on Sunday – in the last eight, following the Croat’s 7-6 (8-6) 6-4 victory against Russian Ludmilla Samsonova.
In the men’s draw, Italian sixth seed Matteo Berrettini overcame South Africa’s Lloyd Harris 6-4 7-5 to set up a fourth round meeting with Serbia’s Miomir Kecmanovic, who beat Dutchman Botic van de Zandschulp 7-6 (7-3) 7-5.
American 20th seed Taylor Fritz beat Spaniard Jaume Munar 6-4 2-6 7-6 (7-2) and will face Alex de Minaur next, after the Australian defeated American Tommy Paul 7-6 (7-2) 6-4.
Britain’s defending men’s champion Cameron Norrie progressed to the last 16 on Monday. He plays American Jenson Brooksby on Wednesday.
