Nine men Town suffered a 7-1 defeat to Peterborough despite taking the lead at London Road through Keith Andrews.
Lee Martin and Tommy Smith were both dismissed for Town during the game, as Posh came from behind to net seven goals, with Paul Taylor and Grant McCann bagging a brace each while Lee Tomlin went one better by scoring a hat-trick.
Town made four changes to the side that lost to Southampton last time out, with Martin and Jay Emmanuel-Thomas both being recalled to the starting line-up, while Lee Bowyer missed the game with a hamstring injury.
There were also first starts of the season for Josh Carson and Jack Ainsley, who was also making his first ever League start for Town.
The game started at a fast pace and Town 'keeper David Stockdale had to be alert early on to keep out a McCann free-kick that he tipped over the bar.
From the resulting corner Stockdale made an equally impressive save as he denied Scott Wooton from opening the scoring with a powerful header after making a point blank save.
Town hit back through Emmanuel-Thomas, who flashed a shot just wide of Paul Jones' post after 10 minutes.
Shortly after a good move involving Carlos Edwards and Carson saw the winger cross for Michael Chopra but his shot failed to hit the target.
After a quarter of an hour Martin tried his luck from the edge of the box but his curling effort went just over the bar with Jones well beaten.
The deadlock was finally broken in the 23rd minute courtesy of a long distance strike from Andrews that flew into the top corner.
Good work from Edwards saw him flick the ball on to the Republic of Ireland international and he unleashed a thunderous shot which went into the top corner via the post.
However the hosts were soon back on level terms as Taylor scored his first of the afternoon on the half hour mark, finishing from just inside the area after Lee Frecklington had pulled the ball back
.Eight minutes later and it was 2-1, with Tomlin finishing into the top corner after turning Edwards inside the box.
Just a minute later and Taylor scored his second and Posh's third with a prodded finish into the bottom corner.
Things got worse for Town after 41 minutes as after Tomlin shrugged off Ainsley before calmly finishing past Stockdale to make it 4-1 to the hosts.
Town were then reduced to 10 men a minute before half-time, after Martin was dismissed for a tackle on Frecklington that the referee deemed worthy of a straight red card.
Smith was introduced at the break as he replaced Carson, but he was heading back to the dressing room a minute later after bringing down Tomlin and giving away a penalty.
Skipper McCann stepped up to take it and fired emphatically into the net to make it 5-1 two minutes after the restart.
Posh- and McCann- were celebrating again soon after, when the midfielder scored again after 55 minutes.
Good work by Frecklington down the right hand-side saw him cross for McCann whose shot deflected off Ainsley and into the net.
By now the hosts were in control of the game and went close through George Boyd and substitute James Tunnicliffe, who struck the post late on.
Boyd also produced a fine stop out of Stockdale to deny his right footed drive, while full-back Craig Alcock also went close with a shot that went just over the bar.
Tomlin finally completed his hat-trick in the third minute of stoppage time as fired into an empty net after his initial shot was blocked on the line by Aaron Cresswell.
Town will be looking to bounce back from this disappointing defeat and are back in action next Saturday when Leeds visit Portman Road, kick-off 3pm.
Posh: Jones, Little (Gordon 55), Alcock, Bennett (Thompson 55), Wooton, McCann, Rowe, Frecklington (Tunnicliffe 59), Boyd, Tomlin, Taylor. Subs not used: Day, Gordon, Thompson, Ball. Booked: Tomlin, Frecklington.
Town: Stockdale, Edwards, Cresswell, Delaney, Ainsley, Leadbitter, Andrews, Carson (Smith 46), Martin, Emmanuel-Thomas (Kennedy 53), Chopra (Ellington 70). Subs not used: Lee-Barrett, Scotland. Sent off: Martin, Smith. Booked: Leadbitter, Cresswell, Delaney.