Peterborough United played over 70 minutes with 10-men at the ABAX Stadium against an in-form Bury secured a late victory with substitute Tom Pope heading the winner with his first touch of the game.
Erhun Oztumer was sent-off after just 23 minutes for a late tackle and despite battling gamely with the numerical disadvantage, Posh were eventually undone in the closing stages by a talented Bury side.
The opening exchanges were dominated possession-wise by the visitors, but apart from a wayward header from Leon Clarke, there was no real threat to the Posh goal.
Marcus Maddison, who had already showed some neat touches, tested Lainton with a low right-footed effort on the quarter hour mark after a strong run.
On 23 minutes, Posh were reduced to 10-men as Erhun Oztumer was shown a straight red card for a late challenge on the edge of the Bury box. It looked a harsh decision on first viewing, certainly there were no real howls of derision from the Bury players, but referee Mr Martin was adamant.
The deadlock was broken on 27 minutes as Leon CLARKE raced onto a through ball and dinked the ball over the advancing Alnwick.
Maddison demonstrated excellent control and then displayed incredible vision to have an audacious effort from fully 45 yards, but his shot sailed just wide.
Posh then appealed in vain for handball as Maddison clipped the ball into the box, but the referee waved away protests. Coulibaly then dragged a shot wide after cutting inside from the left.
On 43 minutes, Posh levelled the scores as a corner from the right by Maddison was glanced past Lainton and into the back of the net by Gabriel ZAKUANI for his first goal of the season.
Tom Soares dragged a shot wide of the target two minutes after the re-start as Bury went in search of a second goal.
However, moments later, Posh were in front and it was that man ZAKUANI again, this time meeting a Jon Taylor corner kick and powering a header via the inside of the far post and into the back of the net.
On 57 minutes, Posh had a great chance to make it 3-1 as Angol raced onto a superb Smith through ball, but his audacious chip went wide of the target.
On 64 minutes, the visitors found a leveller as Nathan CAMERON fired home on the volley from close-range as Posh failed to clear a diagonal ball.
Manager Graham Westley responded by introducing Conor Washington for Angol in attack.
Peter Clarke drifted an effort wide of the target on 68 minutes as the Shakers began to dominate with Posh understandably tiring. Alnwick denied a curler from Riley on 73 minutes as Bury pressed.
Maddison was denied by Lainton at the near post and from the resulting corner kick, there was panic in the Shakers defence, but Santos hooked his shot over.
Leon Clarke somehow headed wide unmarked on 78 minutes after a cushioned ball into the box by Pugh as Posh had a lucky escape.
The Shakers got themselves ahead in the game on 80 minutes as substitute POPE powered home a header from a driven Riley corner kick with his first touch.
Maddison fired wide of the near post moments later after bursting into the box on his right-foot. Taylor fired over on the half volley from a Maddison corner kick while Maddison fired a free-kick into the wall.
Posh: Alnwick, Smith, Zakuani, Almeida Santos, Elder, Forrester (sub Davey 56min), Bostwick, Oztumer, Maddison, Angol (sub Washington 65min), Coulibaly (sub Taylor 46min). Unused subs: Henry, Fox, H. Anderson, Collison.
Bury: Lainton, Riley, Hussey, Clarke, Mellis (sub Hope 46min), L. Clarke, Mayor, Jones (sub Rose 46min), Soares, Pugh, Cameron. Unused subs: Ruddy, Pope, Sedgwick, Folds, Brown.
Half-time: Peterborough United 1-1 Bury
Full-time: Peterborough United 2-3 Bury
Attendance: 4,208 (190)