One outstanding strike from John Johnson condemned Dagenham and Redbridge to a third successive defeat in League Two.
John Still made several changes on his return to the sidelines. Damien McCrory, as expected was included, but the selections of Darren Currie, Jon Nurse and Wes Thomas was perhaps more of a surprise. His side's performance deserved more than a single goal defeat.
It was a cagey opening from both teams, with aggressive defences at either end of the pitch largely on top.
Paul Benson had the first attempt of the afternoon but Chris Dunn in the Northampton goal was hardly tested by his weak header.
Thereafter both keepers had very little to do. Adebayo Akinfenwa and Luke Guttridge couldn't get their attempts anywhere near on target while the same could be said of both Paul Benson and Thomas.
Nevertheless McCrory's first outing for the Daggers was certainly a positive for the Dagenham and Redbridge manager and the full-back linked up well with Currie on the left.
The sides' finally mustered an effort on target after half an hour. Tony Roberts clawed away a glancing header from Akinfenwa.
That sparked a decent end to the opening half from the Daggers. Marlon Pack volleyed high and wide while a Peter Gain cross was flicked across goal by Nurse only for the ball to fly just too high for Benson hovering at the far post.
Thomas perhaps had the clearest opportunity during this spell, his volley was blocked by the Cobblers defence. Northampton broke immediately from that opportunity and their counter-attack culminated in Billy Mckay clipping the ball just over the crossbar.
The half finished with the Daggers just about surviving a scare. Former Dagger Dean Beckwith got on the end of a Northampton corner but the home side scrambled the ball away to safety.
Chances at both ends came after the restart. For the visitors Andy Holt smashed a half volley as the ball rocketed just past the post.
The Daggers forced a flurry of corners which came to no avail. Thomas did hold off Craig Hinton to strike at goal, but he dragged his effort wide.
The game threatened to open up just after the hour mark. Akinfenwa jumped onto a loose ball in the Daggers area. He toe-ended the ball over Roberts only to see it land on the roof of the net.
The home side responded as Gain threaded a super pass for Nurse. The former Stevenage man struck powerfully on goal but he was denied by what looked like to be a super fingertip save from Dunn, although the referee thought otherwise as he signalled a goal kicked.
Josh Scott was brought on from the bench given the instruction to add his presence to the Daggers attack while Danny Green was also brought on from Currie.
Moments before Currie left the field he swung over a corner that Scott Doe headed straight at the keeper.
The home side might have thought that Beckwith was lucky to escape punishment after it looked like he clashed with Benson with his elbow.
The Daggers wounds would have deepened with just a little under twenty minutes remaining,. Northampton's Johnson cut inside from the right flank and unleashed an unstoppable shot into the top corner to give the Cobblers the lead.
If there were one player who could have inspired a Dagenham comeback it was Gain. After putting a terrifically committed performance Gain struck a magnificent volley that would have beaten many goalkeepers in League Two. However Dunn produced a stupendous one handed save to keep his side ahead.
Phil Walsh was Still's final change as the Daggers looked for a point that their performance deserved. Benson had two headers neither of which could he direct on target while Northampton defenders threw themselves at efforts from both McCrory and Gain. In the end it just wasn't to be.
Att: 2, 206 (668 Northampton)