Twice Burleigh opened up a 10-point lead over the Dolphins but a try from late Redcliffe inclusion Darren Nicholls 16 minutes into the second half narrowed the margin to just four points.
The two teams were locked in a tense duel for the next 10 minutes as the Dolphins looked for the go-ahead try but it was Cullen who capped a brilliant individual display with a try in the 70th minute that would ultimately seal their second Intrust Super Cup title.
