Darren Ferguson's return to Peterborough proved to be a thoroughly miserable one as his Doncaster Rovers team were comprehensively beaten.
Rovers went to London Road in search of back-to-back wins under their new boss but they were put firmly in their place by Graham Westley's attack-minded Posh.
Gabriel Zakuani gave the hosts an early lead with a free header from a corner, and the home side doubled their advantage when Erhum Oztumer stroked home to cap a dominant first half display.
Ferguson shuffled his pack at half time in an attempt to contain United but the hosts put the game to bed within 60 seconds of the re-start when Callum Elder beat Thorsten Stuckmann from inside the box.
Conor Washington rubbed salt into Rovers' wounds with a fourth goal in the final quarter of the game.
Ferguson made two enforced changes replacing injured pair Keshi Anderson and Gary MacKenzie with Andy Williams and Luke McCullough.
The Scot would have been hoping to see his side carry on where they left off at Shrewsbury on Tuesday night - but an abject first half display would have left him seething.
The first 45 minutes could not have been more one-sided as Peterborough completely dominated the midfield and got in behind Rovers time and time again.
Oztumer had already curled a free kick just wide and forced a full length save from Stuckmann before Posh went ahead after nine minutes, Zakuani heading in Oztumer's corner virtually unchallenged.
It was the way the hosts were cutting through at will that will have caused most alarm, as Doncaster had no answer to United's intricate midfield play and also looked horribly susceptible to balls over the top.
Souleymane Coulibaly smacked one against the inside of the post and Washington got clean through only to fluff his lines before Oztumer did double the lead on 36 minutes, calmly stroking home after good hold-up play from Coulibaly.
Aaron Taylor-Sinclair replaced Richard Chaplow at the break, with Rovers switching to 3-5-2 in an attempt to contain a rampant home team. But the visitors found themselves three down inside the first minute of the second period.
Marauding left back Callum Elder's long range hit struck Andy Butler but the rebound fell kindly for Elder who found himself in all sorts of space to guide an effort past Stuckmann and put the game out of Rovers' reach.
Butler saw a header cleared off the line from a corner and Nathan Tyson was unlucky to see his clipped effort come back off the inside of the post as Doncaster tried to regain some lost pride.
But, despite Doncaster seeing a bit more of the ball, Peterborough continued to carve open the Rovers defence - and Washington added the gloss to a comfortable victory when he robbed James Coppinger of possession and slammed home from 25 yards.
Peterborough: Alnwick, Bostwick, Zakuani (Smith 15), Santos, Elder, Anderson (Fox 68), Oztumer (Angol 74), C Forrester, Taylor, Coulibaly, Washington. Subs not used: Henry, Vassell, Davey, Collison.
Rovers: Stuckmann, Lund, McCullough, Butler, Evina, Wellens (Middleton 54), Chaplow (Taylor-Sinclair 46), Coppinger, Stewart, Tyson, Williams (Forrester 56). Subs not used: Marosi, N'Guessan, Keegan, Horsfield.