Top seed Kristina Mladenovic was forced out of the Samsung Open in Lugano with injury as she retired during her match with German qualifier Tamara Korpatsch with a back injury.
Mladenovic was already a break down in the second set, having the lost the first, and called it a day with the score 7-6 (7/5) 3-2 in Korpatsch's favour.
"I don't like to win like this, that she retired," Korpatsch said in quotes published on wtatennis.com.
"I don't know if she was already injured at the beginning, or if it happened in the match."
Fourth and fifth seeds Anett Kontaveit and Svetlana Kuznetsova were both eliminated too despite winning the opening sets in their respective contests.
Qualifier Vera Lapko beat Kontaveit 3-6 6-4 6-3, while Mona Barthel recorded a 4-6 6-3 6-4 victory over Kuznetsova.
At the Claro Open Colsanitas in Bogota, the weather won as play was suspended and a number of matches rescheduled.
Before the deluge, number one seed Tatjana Maria was knocked out by world number 191 Daniela Seguel 6-3 6-1 but number three seed Johanna Larsson saw off Valentini Grammatikopoulou in three sets 4-6 6-4 6-4.
The match between Anna Blinkova and Ana Bogdan will resume on Friday at 6-1 7-6 (10/8) 2-2, while Magda Linette takes a one-set and two-game lead in her match against Maria Fernanda Herazo 6-2 3-1.
