Jamie Cureton twice went close for Shrewsbury before Dave Hibbert had a shot saved by Nick Colgan, but then Grimsby went ahead through a penalty when Akpro was felled in the box by Kelvin Langmead. 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.
Source: Team Talk
Source: Team Talk