No. 1 seed Karolina Pliksova was upset by Brazilian Beatriz Haddad Maia 6-3, 7-5 at the BNP Paribas Open.
World No.115 Haddad Maia had lost to Usue Maitane Arconada in the final round of qualifying, but got a second chance after the withdrawal of Nadia Podoroska as a lucky loser.
In windy conditions, Haddad Maia was the steadier as Pliskova struggled with her serve, hitting seven double faults in the first set.
The second set saw eight consecutive breaks of serve, before Haddad Maia dropped her service while serving for the match at 5-3.
Then at 6-5, Haddad Maia fired a return winner, taking out the match after another Pliskova poor return.
Haddad Maia will next face No.18 seed Anett Kontaveit of Estonia.