The Londoner beat the Scot is a pulsating match that could have gone either way, but Maguire missed a chance to capitalise on a fluked red after escaping from a snooker in the seventh and final frame. His break dried up on 41, and Gould cleared to the blue to secure the title 4-3.
The match was fiercely contested from the beginning, the players being tied at 1-1 and 2-2 before Gould got his nose in front by winning the fifth frame on a respotted black.
But Maguire once again fought back into it to push the match to a decider before Gould came through to win the first title of his career that carries ranking points.
It feels amazing to win a tournament with ranking points for the first time," said the world number 16. "My aim now is to win some big titles."
Gould explained that new coach Stephen Feeney had been the key to his win.
"He noticed a fault in the way I was sighting the ball and fixed it straight away," he said. "The improvement has been beyond my expectation and every time I was among the balls this week I felt as if I was going to clear up.
"I lost a lot of close matches at the end of last season and I realise now that was because of the problem with my sighting and cue action. It feels great to know it is fixed."