Australian Open champion Sofia Kenin beat Anna-Lena Friedsam 6-2 4-6 6-4 in the final of the inaugural Lyon Open.
Kenin, 21, is the first player on the WTA Tour to win two titles in 2020 but a number of unforced errors gave unseeded Friedsam, 26, the second set.
The United States' world number five regrouped in the final set, earning a double break before clinching victory on her third championship point.
"It's such a tough tournament, it could have gone either way," Kenin said.
German Friedsam was in her first final since 2015 as she continues her comeback from a shoulder injury.
"You've come back from injury and you're doing well and I wish you all the best for your upcoming tournaments," Kenin added.
It was the fifth title of Kenin's blossoming career after her three triumphs last year in Hobart, Mallorca and Guangzhou - before beating Garbine Muguruza in the Australian Open in January.