The Hong Kong potter only finished fourth in the group stage of the Winners' Group but was then in scintillating form in the knock-out stage.
First he annihilated Stephen Maguire 3-0 in the semi-finals with consecutive big breaks of 111, 94 and 95. Maguire scored just seven points in the match.
He then looked to be trouble against Allen in the final as he went 2-0 down but he then got himself back into it by winning a tight third frame before a break of 94 made it 2-2.
Fu then saved the best for last as a total clearance of 134 won him the tournament.
He received a cheque of £10,000 for victory in the Winners' Group with his earnings over the course of the tournament topping £25,000.
Fu will have a chance to add to those earnings with an automatic berth into the lucrative Premier League an added bonus to winning the Championship League.
Stephen Maguire 0-3 Marco Fu
Mark Allen 3-2 Neil Robertson
Marco Fu 3-2 Mark Allen