Ferguson believes Posh, who ousted Newcastle in a 2-0 Carling Cup third-round win, have focused on their league form in recent seasons as the London Road outfit plotted their climb from League Two.
He said: "We've not really done well in the cups since I've been here because the league has been very important to us, but I think it is about time we had a good run.
"Our passing and movement was good and that was the key. The tempo we played at was good. We knew their team was a youngish one so we had to be in their faces and play at a high tempo.
"We played at a tempo they could not live with and it was very pleasing. If we had got a third it could have been anything.
"We should have scored more but their goalkeeper was outstanding."