Doug Loft cancelled out Adebayo Akinfenwa's early strike, but goals from Abdul Osman and Billy McKay ensured the Cobblers cruised to their third successive victory and are now within three points and one place of the play-off pack.
Sampson said: "It was another very good day for us. Other results have also gone our way which has also helped and I've just come out of a very happy dressing room.
"People saw both sides to our game because we played some great stuff in the first half to go ahead and then showed our resilience after the break.
"I thought our passing and movement on what must be one of the biggest pitches in the league was excellent in the first half. Our link-up play was very good and we scored some good goals.
"To be fair to Vale it was a bit like the Alamo in the second half and we had to throw our bodies on the line to put the blocks in. Fortunately, we didn't concede and our two-goal cushion gave us some breathing space."
Source: Team Talk
Source: Team Talk