Portsmouth moved off the foot of League One as two goals from veteran striker David Connolly saw them earn their second successive victory at the expense of Bury - who are now bottom.
The Shakers had the better of the first-half chances but Craig Fagan was erratic in front of goal.
Connolly gave Pompey the lead after sweeping home from six yards out.
And he doubled their tally from close range after keeper Trevor Carson failed to hold Johnny Ertl's powerful drive.
The result, Portsmouth's first victory at Fratton Park since 20 October, means Bury are bottom on goal difference with Pompey above them and the pair eight points from safety.
VIEW FROM THE DRESSING ROOM
Portsmouth caretaker manager Guy Whittingham tells BBC Radio Solent:
"We weren't happy with our first half performance, they were a lot better than us. The only positive I can take out of that first half was it was still 0-0.
"It's hard sometimes at half time when you haven't played well, you know you haven't played well, and yet you've got to go out and turn it round. I think the credit must be given to the players because they've turned it round today.
On David Connolly, Whittingham added: "I had the advantage of playing alongside him a while ago and I know what sort of character he is,
"I know what sort of player he is…the finishes were fantastic finishes. The calmness for the second one and the ability just to pick his spot with the first one with the side foot finish that's really helped the team today because the confidence grew from that."