Hart and Fry's post match comments
"In terms of result and scoreline, we've been threatening to do that and the lads felt someone would be on the end of a hiding," he said.
"I thought we were poor in the first half, but to be fair to them they livened up in the second half and the front two played together a bit better.
"It's a good scoreline and we've moved a bit in the table which is encouraging."
Peterborough manager Barry Fry said: "We've got to improve on that because we were abysmal,"
"There was nothing good about us at all. Barnsley ripped us apart. Every time they went forward they looked like they would score.
"It's about time someone beat us 4-0. We've had nine 1-0 defeats, and this result shows that we are miles away."