The British No. 1 lost three service games in the first set, but was able to secure four breaks of her own to take the set in 40 minutes.
The No. 26 seed wrapped up victory against Lottner, 22, after winning a second set that also lasted 40 minutes and produced the same 6-4 scoreline as the previous set.
While Konta is not known to be particularly adept on clay, she is currently on fine form on the surface, having finished as runner-up to Karolina Pliskova at the Rome Masters two weeks ago, with wins over Venus Williams and top 10 seeds Sloane Stephens and Kiki Bertens on the way to the final.