The biggest crowd of the season at Victoria Road witnessed a stunning and ruthless performance from the hosts as they took the lead after 20 minutes when Paul Benson laid the ball off to Sam Saunders, and he stroked him his fourth goal in four games.
Ben Strevens had a shot cleared off the line before it was 2-0 after 34 minutes as Solomon Taiwo crashed home a stunning volley from 20 yards.
The Bees almost pulled one back before the break, but Marcus Bean saw his close-range shot expertly saved by David Button after Billy Clarke played him in.
It got even better for the home side after the break as Saunders curled a wicked corner to the far post, where Mark Arber headed into the net via the post.
Brentford were slightly better in the second period as Sam Williams fired a shot over the bar as did Sam Wood, before the Bees did pull one back six minutes from time when substitute Damian Spencer pounced after a melee in the box.