In reality the game was over as a contest inside 12 minutes as the home side swept into a two-goal lead that they never looked like losing.
Rochdale should have had a penalty within 35 seconds of the kick-off when midfielder Clark Keltie was upended in the box but referee Kettle, who had a poor game throughout, waved away the appeals.
It didn't take long though for that to be forgotten as winger Adam Rundle was allowed to cut in from the left and fire in a low right-footed drive that took a deflection on its way past stranded goalkeeper Wayne Henderson.
Rochdale doubled their lead in the 12th minute when leading scorer Adam Le Fondre raced on to a pinpoint pass from full-back Tom Kennedy to comfortable finish for his 15th goal of the season.
Without a win in seven games, Grimsby rarely threatened but did almost equalise in the 39th minute when Adrian Forbes saw his powerful drive brilliantly tipped onto the crossbar by home keeper Frank Fielding.
Though Grimsby improved slightly in the second period they again produced no real goal threat and it was the home side who continued to look the most likely with Le Fondre and substitute Joe Thompson going close twice to extending their lead.
In the dying seconds Rundle was denied by an excellent Henderson save and another substitute, Chris Dagnall, wasted an opportunity when put through by Kennedy.