Trailing to a Freddie Sears goal in the Johnstone's Paint Trophy at Sixfields, the Cobblers fought back with strikes from Bayo Akinfenwa and Henoc Mukendi to make it into the next round.
The visitors from League One were reduced to ten men in the dying stages of the game as they fought in vain to take it to a penalty shoot-out.
Having seen his old club defeated, Aidy Boothroyd will now look for his side to end their mini-slump in League Two at the weekend when Exeter City are the visitors.
Source: FOOTYMAD
