Charlie Wyke put the visitors in front after just a minute but from then on it was one-way traffic at Sixfields as Chris Wilder's side moved up into 5th place in League Two.
Marc Richards scored twice as did the returning Kaid Mohamed, Lawson D'Ath also getting his name on the scoresheet.
The vast majority of the 3,653 crowd were royally entertained and plenty more should come through the gates on Saturday when Accrington Stanley are the visitors.
Wilder beamed afterwards: "It was a great reaction from Saturday's performance at Newport, which was very disappointing. But you tend to have one of those sort of games each season and hopefully that was ours.
"We had an attacking side out there and we moved the ball around very well. We had plenty of movement, the front two worked very well for us, and it was a joy to watch my team play."