After conceding 80 points in their losses to the Broncos and Sharks, the Red V discovered their defensive resolve to restrict the Dolphins to just two tries.
As is so often the case, skipper Ben Hunt was the driving force behind the victory with a try, seven tackle breaks and a try assist as the Dragons spoiled the party for rival captain Jesse Bromwich's 300th NRL game.
Dolphins winger Jamayne Isaako had a chance to open the scoring in the 12th minute after Jacob Liddle was penalised for a strip but the attempt sailed wide.