Steve Schumacher and Rowan Liburd gave Boro a two-goal lead inside 17 minutes and despite Northampton turning the game on its head with three goals in 12 minutes, first year scholar Ben Wilmot equalised with a bullet header from Michael Tonge's corner before the break.
Liburd scored his second six minutes into the second half and Boro caused plenty of problems going forward with Jake Hyde twice hitting the woodwork, Tom Pett firing over and Liburd seeing a hat-trick chance thwarted by the Northampton 'keeper. However two further goals from the Cobblers - who included the likes of Joel Byrom, Alfie Potter, Kenji Gorre (who scored a hat-trick) and Lawson D'Ath in their XI - sealed the victory.
Reflecting on the game coach Nicky Shorey told us, "The positives were the way we passed the ball, the positions we got into and the chances we created and we should have scored more if I'm honest. However you can never be happy when you concede five goals. It's a great learning curve for the younger players. They need to learn from that and realise what it takes to push up and join the senior group."
Rowan Liburd scored twice in the game and Shorey said he was pleased with the striker's contribution.
"A striker scoring goals is only going to help confidence," he said. "I thought he and Hydey were excellent up there and a real handful. I don't know how Jake hasn't scored to be honest - the 'keeper's made one great save, he's hit the post and he should have scored with a side-footed finish.
"Both were really positive with their movement and their manner and that's what you want from your two strikers. You want them being positive, closing down from the front and leading and I think they did that today."
Stevenage XI: Day, Wilmot, Croud, Omar, O'Keefe (Dowridge 73), Pett, Tonge (Fraser 73), Schumacher (Guerfi 46), McKee, Liburd (Ofosu 85), Hyde