Ricky Holmes insisted he bore no grudges over Andy Awford’s decision to jettison him from Fratton Park.
But the winger’s actions suggested otherwise as he turned in an all-action display to predictably topple Pompey.
Booed from the start by the 798 Blues followers gathered behind the goal he was attacking in the first half, it took a moment of magic from the 27-year-old to break the deadlock.
Receiving Northampton team-mate Chris Hackett’s throw and cutting in from the right, Holmes curled in a left-foot shot from inside the box into the far bottom corner of the net.
In a tight contest between League Two’s form sides, it was enough to settle matters, much to the delight of the ex-Pompey man, who didn’t bother to disguise his glee after netting the decisive goal.
For Awford, it was the end of a total of seven matches without defeat which have put him on the verge of a well-deserved League Two manager-of-the-month accolade.
What a run it had been, too, yet they couldn’t quite find a way past Matt Duke despite a strong finish to a contest which was always fiercely contested.
There were opportunities, Duke saving from Paul Robinson and Matt Tubbs, while Ryan Cresswell headed another Tubbs effort off the line late on.
Ben Chorley was sent off in stoppage-time for a second yellow card, while there was also the welcome sight of Wes Fogden coming off the bench for a first appearance of the campaign.
Yet it was to be the Cobblers’ and in particular Holmes’ night as the forward was given a standing ovation in the 84th minute after being substituted.
The home fans even chanted ‘One Andy Awford’ following the predictable announcement of the identity of man of the match.
Not that Pompey have suffered since his January departure, far from it as they rose to the top of the form table.
Now it’s time to build again at Accrington on Saturday to ensure the Sixfields defeat was nothing more than a blip.
Awford named an unchanged side from the one which lined up against Oxford United for Saturday’s goalless draw.
With Jack Whatmough still to recover from the ankle injury which kept him out of that fixture, Chorley continued in the back three and also skippered the team.
James Dunne was another who remained on the sidelines, serving the second game of his two-match ban – having totted up 10 yellow cards.
There were also no alterations to the bench, the same seven from Saturday on duty for last night’s Sixfields Stadium trip.
Among them was Fogden, who made such a welcome return to the match-day 18 for the previous fixture following long-term injury.
Despite Paul McCallum now being available again after a seven-game suspension, he was not recalled to the squad, with match practice required.
Meanwhile, Nicky Shorey and Patrick Agyemang continue to miss out on first-team action and Tom Craddock is still undergoing his rehabilitation.
It took just three minutes for ex-Blues winger Holmes to get in his first cross, delivering a dangerous ball from the left which Chorley came across to clear for a throw-in.
In a fast-paced opening, Holmes then cleverly cushioned a lay-off into the path of Ivan Toney, whose right-foot shot from inside the box was straight at Paul Jones.
Then Chris Hackett delivered a corner from the left and it was met by Jason Taylor’s far-post header which flew wide.
On 10 minutes, great work from Jed Wallace down the left inside the box resulted in a flighted cross which Ryan Taylor could only head straight at Duke.
Holmes was attracting boos from the travelling supporters behind the goal he was attacking but it was a lively start from the midfielder, mainly focused on the left-hand side.
At the other end, Dan Butler flighted in a corner from the left which was powerfully met by the head of Robinson at the far post.
But it landed on the roof of the net rather than troubling Duke.
On 23 minutes, good work from Tubbs down the left saw him roll the ball into the path of Josh Passley.
He had plenty of time to line up a shot which flew comfortably over the bar from the angle.
The deadlock was broken in the 25th minute.
A piece of excellence from that man Holmes ensured the hosts grabbed the advantage.
Hackett took a throw-in from the right to feed the winger and he cut across the penalty area before curling a delicious left-foot shot into the far corner.
There was no restraint in Holmes’ celebration either, making the most of the moment by hurtling towards the main stand adjoining the away section to celebrate.
The goal-scorer had the bit between his teeth.
He ran rings around Butler with a marvellous piece of skill only for Toney to be called up for a foul as the hosts attempted to capitalise.
Pompey were struggling to get back into the game and, while Danny Hollands was off with a bloodied face, Toney spun and fired in a fierce shot which deflected for a corner.
The visitors responded well on 40 minutes, Lee Collins ballooning a header up into the air inside the penalty area and Tubbs volleying it goalwards once it had dropped.
Duke did superbly to block his powerfully-struck effort and the Cobblers scrambled the ball clear to breathe a collective sigh of relief.
The first half closed with a strong run from Nigel Atangana followed by a fierce shot from the angle which whistled just over.
There were no changes at the interval, although Robinson almost gifted a corner from the kick-off with a header back towards his own keeper which lacked accuracy.
In the 50th minute, a Pompey counter attack saw Taylor play in Passley whose angled drive from the right flew just wide of the far post.
The Cobblers made a substitution in the 55th minute with top-scorer Marc Richards replacing the quiet Lawson D’Ath and moments later Awford made a double change.
Pompey’s boss brought on Andy Barcham for a clearly-disgruntled Passley, while Craig Westcarr took the place of Atangana.
In the 62nd minute, Holmes twice blocked attempted clearances from Robinson and when it appeared Richards had managed to go clean through on to the loose ball, Wallace popped up to clear.
The match was still delicately poised, however, and when Barcham was put through down the right by Tubbs he should have done far better than the cross to no-one which was delivered.
Then a corner from the right was met with a Robinson far-post header which was clawed away by Duke from a standing position as the hosts began to rock.
On 73 minutes, Robinson headed Richards’ shot off the line with Jones nowhere to be seen after the striker had initially blocked his clearance outside the box.
Fogden was brought on in the 78th minute and immediately had a goal-scoring opportunity when Wallace fizzed in a cross from the right but he slid the ball over the bar.
The visitors were finishing strongly and a lovely piece of juggling from Tubbs was then met with an angled shot which Duke saved low down.
Then Cresswell had to head Tubbs’ back-post effort off the line after Wallace had whipped in a teasing cross from the right.
Chorley received a second yellow card in four minutes of stoppage-time – following an aerial challenge – to weaken the visitors’ numbers but there was no coming back as it finished in a Northampton victory.