Manager Chris Wilder rotated the starting XI he had chosen for Saturday’s league opener at Bristol Rovers and, while confident about his side’s chances, will have been pleasantly surprised to see Town race into a three-goal lead with less than half-an-hour played.
Chris Hackett opened the scoring before recent signings Sam Hoskins and Dominic Calvert-Lewin put the game out of reach.
Blackpool had no answer to the home side’s attacking prowess and, pleasingly, Northampton continued to push forward despite having a place in the next round in the bag.
The Second Round fixtures, with the majority of Premier League clubs entering the competition, take place in the week commencing 24 August.