Goals from Tommy Rowe, Tyrone Barnett, Grant McCann, from the penalty spot,and Britt Assombalonga gave over 2,000 Posh fans plenty to cheer about as their team made it nine goals in five days, coming after a crushing 5-1 midweek Capital One Cup victory at Colchester.
Dean Leacock had opened the scoring for County in the firs thalf, while substitute Yoann Arquin scored a late consolation penalty in a game which got away from the home side after a decent first period.
"There were a couple of turning points," he said.
"We've scored a great goal early on but then we concede straight away from a set-piece which was disappointing.
"I think there was a penalty there for us but we don't get it and then we concede a soft goal. They also get a penalty where I'm not sure if we catch him.
"Those are major turning points but overall I don't think we've done as well as we can do. We didn't get the ball in wide areas like we should have done, like what we did for the first goal.
"They (Peterborough) are a good team and have been together for a while and pass the ball well. But you've got to stay in the game against these teams and exploit their weaknesses, which are down the wide areas, and I just thought we didn't do that well enough."