Martin Smith ensured his belated birthday celebration was worth the wait by proving a match winner in front of the Sky TV cameras.
Smith, who was 29 last Thursday, executed a vintage 58th minute finish for his sixth goal of the season while putting a dampener on Swansea's impressive away record.
Smith was teed up by Josh Low, who was also the provider for the Cobblers' first goal when he burst between two white shirted defenders before chipping to enable Richard Walker to score with a neat header.
That was in the 44th minute and was just reward for a smart first-half performance by the home side who have now been beaten only once in eight starts under manager Colin Calderwood.
The former Scotland international said afterwards: "I think there were more periods of the game tonight that we can be pleased about.
"It is difficult for me to talk about what happened before I was here. But the advantage of these victories is that we have more of a belief in ourselves." Swansea started the second half with a flourish. In fact, they could have been level immediately after going behind only for leading scorer Lee Trundle to fire over the bar when off balance.
And defender Izzy Iriekpen forced Lee Harper into the half's outstanding save in the 25th minute when the home goalkeeper kept out his shot with his legs when a goal seemed inevitable.
Swans boss Brian Flynn said: "I'm not looking for excuses. We didn't really play and cause them much of a threat." Despite that, this was still a vibrant spectacle and both sides had late chances in a cut and thrust finale.
Swansea's equaliser had an element of fortune as Andy Robinson's fierce drive was deflected into the path of Leon Britton, who smashed the loose ball into the roof of the net.
Trundle then tested Harper with a curling shot from the edge of the box while the Cobblers could have sealed it on the break with Low's pace on the right a frequent source of trouble.
His 85th minute cross was met by the outstretched boot of Walker, whose volley dipped over the crossbar and when he elected to cut inside and shoot himself four minutes later his low drive eluded the far post.