Katie Boulter and Cameron Norrie were knocked out of Indian Wells on Sunday as both suffered straight-set defeats in the third round.
Boulter's run in the women's singles ended as the British number one was beaten 6-0 7-5 by seventh seed Elena Rybakina.
Norrie was earlier dumped out of the men's singles as the British number two lost 6-3 7-5 to 10th seed Tommy Paul.
Their exits mean Sonay Kartal is the last Briton left in the women's draw after claiming a career-best win in California, and Jack Draper the last British male.