Marketa Vondrousova, a 17-year-old qualifier, beat Anett Kontaveit in the final of the Biel Bienne Open in Switzerland to win her first WTA title.
The Czech world number 233 edged Estonia's 99th-ranked Kontaveit - who beat Britain's Heather Watson in the first round - 6-4 7-6 (8-6).
Vondrousova had beaten Czech compatriot and world number 18 Barbora Strycova in the semi-final.
Sunday's victory moves her close to the top 100 for the first time.