Two goals in three second half minutes sealed the 4-0 victory to leave caretaker boss Peter Shirtliff hopeful of landing the manager's job next week.
Mansfield began brightly straight from the kick-off and Gareth Jelleyman almost scored in the first minute with a rising drive.
The best early chance fell to Barnet midfielder Nicky Bailey whose looping header from Simon King's hopeful punt beat keeper Kevin Pressman but landed on top of the net.
Unfortunately King's next involvement gifted Mansfield the lead. King clumsily barged Simon Brown to the ground as the winger raced into the area after incisive passing between Giles Coke, Adam Rundle and Richie Barker. Barker then blasted in his sixth goal of the season from the 11th minute penalty.
Two minutes later Brown's pace again troubled Barnet but, after reaching Rundle's clever pass, he shot into the side netting as the home side threatened to take control.
Four minutes before half-time the Stags again squandered clear chances to seal victory.
Jake Buxton's long through ball released Brown but his fierce drive was blocked by Scott Tynan and, from the follow up, the keeper thwarted Gus Uhlenbeek.
Barnet dominated at the start of the second half and Giuliano Grazioli twice went close to an equaliser before Bailey's far post drive was well held by the keeper.
On a 65th minute breakaway Mansfield doubled their lead, Coke releasing Uhlenbeek who crossed low for Brown to tap in at the near post.
Tynan's outstretched arm denied Uhlenbeek a third goal just three minutes later. But from the resulting well worked short corner Coke was again the provider as Rundle hammered in the killer third goal.
Inevitably Coke also created the fourth goal, his inch perfect pass allowing Barker to round the keeper and roll his seventh goal of the season into an empty net.