Playing in his fourth final of 2022, Tsitsipas looked to have victory in his grasp when he broke for a 3-1 lead in the decisive set.
He surrendered his initiative when he was broken while serving for the match at 5-3.
However, Tsitsipas made no mistake in the eventual tie-break, surging to a 6-4 3-6 7-6 (7-2) victory.
The win secured Tsitsipas' second title of the year after his May success in Monte Carlo.
Tsitsipas will hope his performance on the grass in Mallorca translates to a strong performance at Wimbledon, where he has gone past the first round only once.
He will face Alexander Ritschard in the first round at the All England Club on Tuesday.