For Grimsby it was a sad jolt to their recent revival, on a day when everything fell into place for the home side.
And it was by no means one-sided and Ryan Clarke was named man of the match showing how much of the action the Mariners had.
Both sides suffered early injuries, Grimsby's Stacy Coldicott was off twice with a cut above his right eye and in a little over ten minutes was wearing a third shirt as well as a head bandage.
But it was an injury to Rovers midfielder Paul Trollope which had a more decisive influence on the game.
When Ryan Williams replaced him after 18 minutes, it gave Rovers two wingers. Williams' pace on the left quickly exposed Grimsby and brought a screaming left-foot drive from James Hunt to see Rovers ahead.
Grimsby keeper Tony Williams was having a bad attack of 'drop-itis', and the third time he dropped the ball was relieved to see Thomas Pinault there to head off the line.
Rovers kept the pressure on him and Junior Agogo should have increased the lead when Richard Walker played a ball across the goal. Agogo stretched too late for it.
Another goal was not far away though and Williams supplied it, curling it right-footed past his slow-to-react namesake.
The lead was by no means secure. Straight after the first goal a mistake by Rovers' acting captain Aaron Lescott let in Andy Parkinson for a shot Clarke deflected off his legs.
Then, as soon as Rovers went two up, their left-back Robbie Ryan was blocking a header from Terry Fleming on the line.
With Grimsby's much travelled striker Martin Gritton and his partner Michael Reddy chasing everything, Rovers were often looking to Clarke to keep them on top.
The third goal, with Walker lobbing Williams on the run, kept them there, although the second half was very tight.
It was only Grimsby's third defeat in 13 games.