Jacob Fearnley missed out on a meeting with fellow Briton Jack Draper after losing on his Indian Wells debut to rising star Joao Fonseca.
Knowing a victory would lead to a second-round match against his childhood rival, the 81st-ranked Fearnley led by a break in the deciding set of a thrilling three-set contest.
However, 18-year-old Fonseca recovered to win five games in a row and clinch a 6-2 1-6 6-3 victory.
Draper, seeded 13th, received a first-round bye and will face the Brazilian teenager on Saturday.
Britain's Emma Raducanu followed Fearnley on to the main court at Indian Wells, taking on Japan's Moyuka Uchijima in her first-round match.