Lee Collins’ late own goal against his former club denied the Cobblers a win at Port Vale but the point is enough to secure an npower League Two play-off place.
Collins, who has only ever scored for the Valiants and maintained that record here, sliced into his own net with four minutes to go of a breathless 2-2 draw that saw the home side promoted.
Clarke Carlisle had given Northampton an early lead and Roy O’Donovan restored it with an excellent strike after Liam Chilvers had equalised for the hosts.
The home supporters invaded the pitch at the end of the game but those in the away end will have been encouraged by what they saw, a vastly-improved performance and one that suggests a genuine tilt at promotion through the play-offs may not be out of the question.
In glorious spring sunshine, a carnival atmosphere provided the backdrop for the game, with rosette sellers outside the ground and flags and air horns inside it, each and every supporter excited and expectant.
Groundsmen competed with white, black and yellow balloons as they watered the pitch and the teams emerged to a cacophony of noise from the home supporters that was supplemented by the kind of pyrotechnic display usually reserved for cup finals.
A healthy contingent of fans had made the journey from Northampton too and, upon seeing a team emerge that was without Adebayo Akinfenwa, Joe Widdowson and Clive Platt and containing rookie centre-forward David Moyo, who signed his first professional contract two months ago, will have feared the worst as the game kicked off.
But they saw their side get off to the greatest possible start. Chris Hackett got the better of Daniel Jones in what was the start of a fascinating battle down the wing, winning a corner that the home defence completely failed to deal with.
At the back post was Carlisle, to sweep in like a 20-a-season striker and silence the huge Vale contingent.
Carlisle regularly showed his qualities at the other end too, showing instinct to block Lee Hughes on more than one occasion and using his physical presence to good effect but to the fury of the Vale supporters.
There were slight tactical adjustments while in the lead too - Ben Tozer rarely put a long throw in, an open acknowledgement of the home side’s threat on the counter-attack.
But this was not a Town team sent out to defend their lead - despite Jennison Myrie-Williams looking a threat every time he got the ball there was no deepening of the back four’s line and between them, Hackett and Moyo saw plenty of the ball in advanced areas.
Moyo almost provided an excellent second goal, swapping passes with Guttridge before sliding a pass across goal that the central midfielder rattled against the underside of the bar.
Chris Neal, beaten on the initial effort, then collected the rebound that was headed his way at full stretch by Guttridge.
The home support were stunned at that point but were on their feet moments later when Tom Pope clipped a ball into the box at the second phase of a corner that former Town loanee Liam Chilvers headed beyond Nicholls.
Scenting blood, Vale then watched Lewis Hornby clear Chilvers’ header off the line after the outstanding Myrie-Williams had won a corner on the right wing.
The half-time whistle must have felt like the timekeeper’s bell does to a dazed boxer to Northampton, who were being pinned back with a clockwork efficiency by their resurgent hosts.
The second half was a much more even affair, although Vale still summoned some intensity when they wanted to; Myrie-Williams tested Nicholls’ reflexes with a smartly-struck shot from 25 yards.
There were times when it was no more than a midfield scrap but the away side showed their ability to play football for their second goal, Hornby displaying good patience to pick a pass that O’Donovan spun on and carried towards goal.
Anthony Griffith - who was exceptional for long spells of the game - lost his footing, allowing O’Donovan the time to get the ball onto his preferred right foot and bend a shot past Neal’s right hand and into the top corner.
At that point of the game you could hear a pin drop in Vale Park - except for the noise coming from the away supporters - although voices were raised when a menacing ball, again from Myrie-Williams, fell inside the six-yard box for John Johnson to clear, crucially.
But they grew louder when Collins, the conflicted former Vale defender, sliced a harmless-looking cross horribly over his own goalkeeper to restore parity and bring the crowd to its feet.
It was a bad mistake by an in-form player and was made all the more bitter by the home supporters’ singing of his name as they began their promotion party in earnest.
Five minutes or so later, the home supporters were on the playing surface and the champagne was uncorked in the Vale dressing room.
The Cobblers, though, will have renewed hope that they will enjoying a celebration of their own next month.
Port Vale: Neal, Yates, Purse, Chilvers, Jones, Myrie-Williams, Loft, Griffith, Dodds, Hughes, Pope
Subs: Birchall (for Dodds 73), Morsy (for Griffith 73), Shuker (for Purse 75)
Not used: Johnson, McCombe, Lloyd, Duffy
Cobblers: Nicholls, Johnson, Carlisle, Collins, Tozer, Hackett, Hornby, Guttridge, Harding, O’Donovan, Moyo
Subs not used: Robinson, Akinfenwa, Snedker. Cameron, Wilson, Dias
Away fans: 1,076