They knocked off the event's top two seeds at the Intersport Arena in Linz.
Wickmayer, seeded third, bounced No. 1 seed Flavia Pennetta of Italy 7-6 (7-5), 6-3. The unseeded Kvitova beat No. 2 Agnieszka Radwanska of Poland 6-3, 6-2.
"I've been so close to beating the top players the last few months and now I finally beat one," a joyous Wickmayer said on the women's tennis Web site.
Radwanska, last week's runner-up at the China Open, got trounced 6-3 6-2 by Kvitova.
"I tried, but she didn't give me many chances," Radwanska said.
Sunday's Kvitova-Wickmayer winner will earn $37,000.
Wickmayer holds a 2-1 lifetime advantage in head-to-head meetings between the two.