The 17-year-old Czech booked her first appearance in a WTA Tour final by cruising past her compatriot in north-west Switzerland, coming from behind to win the first set before easily closing out the second.
"It's really amazing. I didn't expect this, but I played really great tennis, stayed focused on every point, and I made it," Vondrousova said.
She will face Anett Kontaveit in the final after the Estonian edged past Aliaksandra Sasnovich 6-4 4-6 7-5.
Francesca Schiavone secured her eighth WTA title by defeating Lara Arruabarrena 6-4 7-5 in the final of the Claro Open Colsanitas in Bogota.
"I'm very happy and emotional," said Schiavone, who is playing her final season.
"This was a disaster match, but winning was the most important thing. Lara is improving a lot.
"I think she pulled a muscle and couldn't run as well that she could, but I thank God that I could win the last three games."
Read the original article on Eurosport: Vondrousova reaches first WTA Tour final in Biel with win over top seed Strycova