Aphinbarnrat and Wattel were locked in a tense battle for much of the final round at The Dutch course before Aphibarnrat capitulated with two double bogeys in the last four holes.
Adding insult to injury was the fact both mistakes came at par-5s, both the result of hitting into water.
Todd Sinnott and Jason Scrivener were the leading Australians at the tournament, the pair sharing 20th position at 8-under and six behind the winner.
Wattel began the final round one shot behind Aphibarnrat but quickly closed the gap with a birdie at the second and went to the turn one ahead as the Thai player struggled.
The three time Tour winner managed just one birdie on the outward nine and the same on the homeward journey while Wattel both gained and dropped shots along the way.
Aphibarnrat’s birdie two at the par-3 14th got the pair back to level but disaster struck at the next when he found water and ended with a seven.
Attempting to put pressure on his playing partner Aphibarnrat tried to reach the par-5 green in two but came up short and notched a second double bogey to fall to a share of ninth.
For Wattel the victory came as somewhat of a surprise in a season where he hasn’t posted a single top 10.
“It feels amazing to win for the first time,” he said after his round. “I am so happy right now.
“I came to the tournament, I was playing poorly to be honest. Last week I struggled with my game.
“I never thought about the score, I just tried to play my best. I was just trying to be as high as I could on the leaderboard but it was very tight.”
Wade Ormsby was next best of the Australians at 7-under and T25 while Ryan Fox (T60) and Sam Brazel (T65) were the last of the Australasians to make the cut.
Andrew Dodt, Brett Rumford, Richard Green, Nathan Holman, Jason Norris and Terry Pilkadaris all missed the weekend.
THE KNOCKDOWN SHOT
Want video tips delivered straight to your inbox? Subscribe to iseekgolf.com newsletters.