Coming into the event, Wattel had 25 top-tens under his belt, including a couple of runners-up finishes, but is now a winner following his impressive closing 69 in the Netherlands.
Highlights included a hat-trick of birdies at the second, fourth and sixth holes as he finished one-shot clear of 20-year-old Canadian Austin Connelly.
The Frenchman's nearest challenger for the majority of day, Kiradech Aphibarnrat, eventually dropped to 12-under par after finding the water on the 18th hole.
Wattel's victory came against the form as he had not finished any higher than 24th this season, and he himself admitted his surprise with the result.
"I came to this tournament, I was playing poorly to be honest," he said. "Last week I struggled with my game.
"I am happy with the way I played all week. It’s been a very nice weekend."