Excellent home form has seen Town get into the thick of the promotion chase and over 5,000 watched them take the lead through Clive Platt and then shrug off the concession of a 65th minute equaliser to seal the points through Langmead and an Akinfenwa penalty.
Both sides enjoyed plenty of chances but the Cobblers' win puts them back into the play-off places.
“At home the players have a belief they are always going to win and so I always thought we’d get back in front even after they equalised," said assistant manager Andy King after the game.
“But we must start to have that same belief away from home. All we need is that away win, I don’t know why we can’t do it away but it’s all about confidence."