Emma Raducanu only decided she would play Thursday's first-round match 20 minutes before play was scheduled to startEmma Raducanu and fellow Briton Jack Draper both won on Saturday to reach the third round at Indian Wells.
Raducanu, the 2021 US Open champion, fought back from 4-1 down in the first set to beat Poland's Magda Linette, the 20th seed, 7-6 (7-3) 6-2.
She will now face either Beatriz Haddad Maia of Brazil, who is the 13th seed, or the Czech Republic's Katerina Siniakova.
Draper, the world number 56, beat compatriot Dan Evans 6-4 6-2.
Raducanu, 20, continued her return to form after shrugging off illness and a recurring wrist injury to beat Danka Kovinic on Thursday.
The world number 77 fought back to win the opening set on a tie-break, then eased through the second set.
Draper, 21, broke Evans, 32, in his first two service games and his last two to knock out the 24th seed.
He could now face another all-British affair as he will meet either Andy Murray or Moldova's Radu Albot in the third round.
