The No. 1 seed battled back from a set down against his French opponent in Antwerp on Sunday, winning a final set tiebreaker on his way to a 3-6, 7-6 (2), 7-6 (4) win.
The victory also provides a major boost to Edmund's chances of qualifying for the season-ending ATP World Tour Finals, which take place in London in November.
"I'm obviously very happy, a lot of hard work goes into this so it's just emotional," Edmund said.
"It's not just me that puts in the work, there's so many guys behind the scenes -- my coaches that are here today, but also those guys back home that have helped me so much throughout the years, my family.
"Gael made me work for it today, that's for sure. I didn't start off well and he was a very tough opponent. Gael ran so many balls down and made me work for it so I really had to dig deep."
"It's only my second final and I've just not been able to string together matches consistently to win tournaments. There's always been something that's let me down.
"It will help a lot to get this monkey off my back. It's great that I've been able to have this experience and come through it. It just gives you so much belief and confidence for the next time that happens."
Couldn't be happier right now! My first ATP Tour Title 🤩🏆 pic.twitter.com/238I3pYSvz— Kyle Edmund (@kyle8edmund) October 21, 2018
Edmund is now a real candidate to make a late run into the ATP World Tour Finals as the race to London heats up.
A successful stint in Asia took him to the quarterfinals of the Shanghai Masters and the semifinals of the China Open in Beijing, earning crucial points in the battle to make the season-ending tournament which begins on Nov. 11 at the 02 Arena.
The British No. 1 is back in action against Argentina's Diego Schwartzman at the Erste Bank Open in Vienna next week before the Paris Masters at the beginning of November.
Even if Edmund performs well in both, he is unlikely to move into the top eight qualifiers with the gap of more than 1000 points to Dominic Thiem difficult to bridge.
All three are also seeded for the tournament in Austria.