Dean Sinclair was the two-goal hero as Grimsby finally ended their 25-game winless run with a 3-0 victory over high-flying Shrewsbury.
The midfielder netted a penalty on the stroke of half-time and added a second after 57 minutes before Jean Louis Akpro fired home the third after 64 minutes.
Grimsby went ahead through a penalty when Akpro was felled in the box by Kelvin Langmead and Sinclair hit the spot-kick low to David Button's right.
Colgan denied the Shrews early in the second half when he raced from his goal to block a shot from Kevin McIntyre, who had broken clear.
The visitors paid for this miss when Grimsby went further ahead. Akpro had a shot saved by Button but Sinclair swept home the rebound for his second of the game.
And Grimsby made it three when Akpro was played through by Lee Peacock and he struck a sweet left-foot volley into the bottom corner.
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