On the pitch, Town were too good for their Sky Bet League One hosts, and off the pitch the travelling support was outstanding.
More than 1,400 supporters made the trip to Staffordshire to cheer their team on, and they were rewarded handsomely for their efforts.
Town raced into a 3-0 first-half lead thanks to goals from Nicky Adams, Ryan Watson and Charlie Goode, and although Burton pulled one back before the break, Sam Hoskins sealed the win in the second half before the home side netted a late, late consolation.
It means the Cobblers are in the hat for the fourth round, which will be broadcast live on BBC1 ahead of Monday night's final third round tie between Arsenal and Leeds United, coverage starting at 7.30pm.
Town are ball number 30 and will be dreaming of drawing one of the big guns next up, which would be a deserved reward for the team and the supporters' efforts at Burton on Sunday.
Photographer Pete Norton was, as always, at the game, and he was on hand to capture these great images of the Town fans enjoying their day out.
Can you spot yourself, or anybody you know?
