The Burleigh Bears joined the competition, becoming the first Gold Coast-based side, while the Bundaberg Grizzlies, Mackay Sea Eagles and Sunshine Coast Falcons all withdrew.
Easts opened the scoring through fullback Leon Yeatman, who broke a number of tackles on a 20-metre run to the try line.
Redcliffe got on the board just before the break, after five-eighth Anthony Singleton crossed easily from dummy half.
With 14 minutes left to play, the Dolphins finally cracked the Tigers' defence, with second rower James Hinchey scoring out wide.
After the siren had sounded, Singleton converted the try from close to the sideline to give Redcliffe their first Queensland Cup premiership.