The Storm put the Roosters on the back foot just after the opening whistle to each half with early tries.
Centre Dane Nielsen was first on the scoreboard in the third minute thanks to some clever lead-up work by halfback Cronk, while tries by Kevin Proctor and Slater helped the home side to a 16-0 halftime lead.
The Roosters appeared hard done by just before halftime when video referee Rod Lawrence was called to adjudicate on a possible try to winger Sam Perrett in the corner.
Despite numerous viewings on the grounding Lawrence ruled no try which prompted Roosters skipper Braith Anasta to approach referee Tony Archer: "Does the benefit of the doubt go to the attacking team? Well he looked at it 1000 times which means he wasn't sure."
Any hope the Roosters had of a second-half fight-back were quickly snuffed out by a Ryan Hoffman try in the 41st minute after an initial Slater break.
The man of the moment then got his second in the 46th minute, followed by one to Will Chambers and the Roosters were looking red-faced.
Hard-working second-rower Boyd Cordner ensured they avoided a dreaded donut with a try in the 73rd minute but it was Slater and the Storm's day, with Cronk adding a second late try to cap the win.
-AAP