Bury dented Mansfield's play off hopes while giving a massive boost to their own chances of staying in Division Three.
The Shakers avenged a 5-3 defeat at Field Mill earlier in the season with arguably their best performance since Graham Barrow replaced Andy Preece as manager.
Bury netted three for the first time since last October but could easily have finished with double that total against a poor Mansfield side devoid of confidence and ideas.
Striker Gareth Seddon finished with two but should easily have collected the match ball while David Nugent, who had a hand in all three goals, twice hit the woodwork including one miss of the season contender.
"This result has been coming," said Barrow whose improved side have now just lost one in 11 games. "There were signs against Rochdale last Saturday that we were coming together and this was an excellent performance.
"But it's nice to get a win after all the draws we've had." After Nugent's amazing miss from virtually on the goal line he then set up Seddon for his opening goal.
Mansfield's cause wasn't helped when they lost Iyseden Christie to injury in the 33rd minute and the visitors' woe was completed just before the interval.
Luke Dimech, a former Bury trialist who had a nightmare match, pushed Nugent and Danny Swailes knocked in the penalty.
Nugent hit the crossbar for a second time just after the break but it was his persistence at closing down Kevin Pilkington that led to Seddon firing home a Matt Barrass centre.
"Gareth and David have been working really hard recently and tonight they got their reward," added Barrow.
Opposite number Keith Curle said: "Football's a simple game but at the moment the players are making it very difficult. We've got to bounce back and we've got to do it as a team, not as individuals."