Ferguson watched his team completely dominate the demoralised home side now on a 12-game run without a victory.
And after this performance, Bury supporters are wondering where the next win is coming from.
The Gigg Lane outfit haven't scored for four matches and apart from a brief flurry late on, they never looked like beating Mark Tyler.
Peterborough, in contrast, were far sharper and more decisive. They swamped the Shakers for the opening half hour, but couldn't find a decent shot to test Andy Warrington.
Amazingly, Bury might have been ahead at the break. Glynn Hurst miskicked after being put clear by on-loan newcomer Tony Bedeau and Andy Bishop blasted wide.
Marc Pugh fired in an early free-kick in the second period but in the space of 12 minutes, Peterborough had the game won.
Craig Mackail-Smith scored his first ever league goal in the 52nd minute after Nicky Wroe allowed a long kick by Tyler to drift over his head.
Four minutes later big defender Ben Futcher powered into the opposite six-yard box. And when Darren Kempson, in his first game on loan from Crewe, unluckily got the ball stuck under his studs, Futcher scrambled in Josh Low's cross.
The match was over as a contest in the 63 rd minute when Gavin Strachan rifled in a low shot after some excellent approach play.
A number of Bury supporters began to leave at this stage, those that stayed booed the Shakers off and rightly so.
Indeed, it was bad case of deja vu for Casper after the previous weekend's thumping by Wycombe.
An experienced player who can organise the midfield is badly needed by Bury if they aren't to slip further into danger.
Peterborough could make a late challenge for the play-offs, but Ferguson shouldn't be fooled into thinking his side has turned a corner.
Bury are very poor and seemed destined for a worrying end-of-season scrap against relegation.