The Cheshire side had not won a League game by more than a solitary goal all season, but under new manager Keith Alexander they have found a new will to win.
A mistake from Ryan Cresswell, however, on 17 minutes could have gifted Barnet an early lead, but striker Adam Birchall could only fire a shot on the turn straight at Jonathan Brain.
Jamie Tolley then warmed the fingers of Lee Harrison with a powerful shot before Macc took the lead on 31 minutes. Neil Ashton delivered a pinpoint cross to the far post for Danny Thomas to nail a six-yard header.
Ashton produced another pinpoint delivery on 41 minutes, which was missed by defence and attack alike, creeping in at the far post with Harrison wrong-footed.
The result was sealed three minutes after the break when Francis Green waltzed in from the left flank before drilling home his 11th goal of the season with a bullet to the top corner.
Macclesfield could have had more goals, Gareth Evans seeing a low shot cleared off the line by Jordan Parkes, before Shaun Brisley looped a curling drive inches passed the far post.
Tolley then saw a scissors kick tipped wide by Harrison as Barnet were continually on the back foot. Birchell might have snatched a late goal for Barnet at the death, but again he picked out the keeper from 15 yards.
After their 5-2 thumping of Lincoln on Saturday, Barnet were found wanting in all departments and seemed like a side with little to play for.