Julia Goerges and Tatjana Maria exited the Ladies Open Lausanne on Tuesday, but Bucharest Open top seed Anastasija Sevastova rallied through.
The shock result of the day on the WTA Tour came in Switzerland, where top seed Goerges, ranked 25th, trailed 6-7 (5-7) 6-4 3-2 to 18-year-old wildcard Simona Waltert when she retired with a wrist injury.
Swiss teenager Waltert said: "The home crowd was pretty cool and I just loved every minute out there."
Goerges lost to French Open champion Ashleigh Barty in the Birmingham Classic final last month but has otherwise endured a tough year since winning in Auckland in the first tournament of the season.
She was joined in making an early exit in Lausanne by compatriot Maria, the fifth seed thrashed 6-1 6-0 by Allie Kiick.
Alize Cornet and Mihaela Buzarnescu, the other seeds in action, both advanced, the latter playing out an improbably topsy-turvy 1-6 6-1 6-0 win over Stefanie Voegele.
In Romania, defending champion Sevastova also won but only after overcoming a scare.
Sevastova lost the opening set to home hopeful Ana Bogdan, ranked 127th, and was taken to a tie-break in the second, before recovering to triumph.
Veronika Kudermetova and Kristyna Pliskova eased through, but fifth seed Sorana Cirstea lost an all-Romanian clash with Jaqueline Cristian.