The 6-4 6-7 (7-3) 6-3 victory was Tsitsipas' first title since he beat Canada's Felix Auger-Aliassime in the Dubai Tennis Championships final in March 2025 and the 13th ATP singles crown of his career.
"I would like to start by mentioning how amazing the final was today," Tsitsipas said. "It's been a long time so it does mean a lot to me."
The 27-year-old, a former world No.3, currently ranked 85th in the world, produced a strong serving performance in the two-hour 17-minute contest on Sunday, firing four aces without a double fault.
He won 21 of 29 points on his second serve and saved two of the four break points he faced.
Tsitsipas took the opening set before first-time ATP Tour finalist Collignon fought back to level the match in a second-set tiebreak.
The Greek regained control in the decider, however, securing the break he needed to seal the title.
The triumph provides a timely confidence boost for two-time Grand Slam finalist Tsitsipas as he looks to build momentum ahead of the US Open, which begins on August 30.
"I'm going back home. I will need one or two days off. It's been a long week," Tsitsipas, now a 13-time tour-level champion, said.
"It's been a lot of crazy matches and I need some recovery and some rest in order to be ready for the American swing. I'm looking forward to trying to do the best possible results in the U.S. swing and in order to do that I'll need to be fresh and prepared for a long few weeks on the road."
10°C