Sam Clucas' goal gave the Stags a half-time lead and they kicked on in the second half with Jamie McGuire and Matt Rhead also finding the net.
It took 31 minutes of a truly dire first half for either side to muster a decent effort, Chris Clements firing just wide from 30 yards for the home side. Four minutes later the deadlock was broken as John Dempster headed on a long Martin Riley free-kick and Clucas was there to flick a header out of the keeper's reach.
A switch to 4-4-2 for the Stags after the break saw them take control and create three quickfire chances, doubling their lead from the third of them, thanks to a keeper error.
First substitute Rhead headed a great close-range chance over, then Clucas was inches wide with a superb 30-yard blast before McGuire finally saw his hopeful 25-yard shot squirm through the arms of goalkeeper Chris Lewington after 48 minutes.
And it was game over 24 minutes later when Rhead turned home a clever back-heel from Calvin Andrew from the left by-line.