Elena Vesnina, fresh off her victory at Indian Wells, crashed out of the Miami Open on Friday after a stunning 3-6 6-4 7-5 loss to number 594 Ajla Tomljanovic.
The Croatian wild card, who led Russia's 13th-seeded Vesnina 5-3 in the third set on Thursday when a thunderstorm halted play, returned on Friday and cashed in on her third match point to secure a spot in the third round.
French Open champion Garbine Muguruza, whose opening match on Thursday was also interrupted, fared better than Vesnina after her night's sleep.
The sixth-seeded Spaniard, who trailed 46th-ranked American Christina McHale 6-0 3-2 when play was suspended Thursday, escaped a match point in the tiebreak and emerged with an 0-6 7-6(6) 6-4 victory.
Vesnina twice double-faulted to present the 23-year-old Croatian with match points after returning on Friday, but Tomljanovic failed to cash in.
Yet another double fault by Vesnina made it 30-40 in the 12th game to put the Russian on the brink of defeat again before a rain shower caused another delay.
This time the wait was worth the while for Tomljanovic. When play resumed the Russian netted a forehand to end it and send the wild card to the third round against Czech Lucie Safarova.
Vesnina, five days removed from the biggest victory of her career at the BNP Paribas Open, committed a dozen double faultsin the two hour 12 minute match.
Tomljanovic, after enduring the tension of such an on-again, off-again huge upset, figures to make time to celebrate with her boyfriend Nick Kyrgios, who is playing in the Miami men's event.
Romanian third seed Simona Halep was pushed to three sets by Japanese teenager Naomi Osaka before advancing 6-4 2-6 6-3, while seeds Timea Babos and Roberta Vinci were also eliminated.