Crewe took an early lead through Ajay Leitch-Smith before new signing Shaun Harrad and Michael Jacobs put the Cobblers 2-1 ahead.
Crewe should have equalised from the spot but Ashley Westwood's penalty was saved by Chris Dunn and three goals in four minutes from Dean Beckwith, Andrew Holt and Abdul Osman put the game out or reach before Billy Mckay added a sixth 10 minutes from time and Antoni Sarcevic scored a late consolation for Alex.
Sampson said: "It was a great result for us, we took our chances well and were clinical in front of goal. I'm delighted to get six goals and for six different scorers to get on the scoresheet.
"I was delighted for Shaun Harrad as players always want to make an impression on their debut and strikers always like to score goals.
"The first half had a bit of everything in it, Chris Dunn made a mistake to give Crewe the lead but then has pulled off a fantastic penalty save to keep us 2-1 up. We got a couple of early breaks in the second half and took full advantage. Everything fell kindly for us but we made the most of it."
Source: PA
Source: PA