Charlton stole victory from the jaws of defeat to set up another celebration after last week's superb win over Liverpool.
South African Shaun Bartlett headed a stoppage time winner after defender Jon Fortune had snatched a shock 78th–minute equaliser.
And it was Paolo di Canio who returned to haunt Pompey manager Harry Redknapp with the corner that brought the late, late winner.
It also provided stunned Portsmouth with their third successive Barclaycard Premiership defeat after they thought they had the proceedings under firm control following a first half strike by their own silky veteran Teddy Sheringham – who grabbed his sixth goal in eight league games.
Redknapp admitted before the start that he wished he had also brought Italian ace di Canio to Fratton Park when he had the chance in the summer, having labelled him his best–ever signing for former club West Ham.
Yet di Canio's contribution should not have mattered, such was Portsmouth's dominance of the game.
There can seldom have been a more one–sided first half in the Premiership this season and the only surprise was that Pompey had just one goal to show for it by the interval.
After successive league defeats which halted their flying start to life at the top, they took a little while to find their rhythm again but once Harry Redknapp's men began firing Charlton were forced firmly on the back–foot.
Sheringham's educated touches continually unhinged the visitors defence and it was entirely appropriate when he made the 34th minute breakthrough with a trademark glancing header from a Tim Sherwood corner which just about defeated Scott Parker's attempt at a goalline clearance.
Earlier Sheringham had provoked a flying save by Dean Kiely, who tipped over his fierce half–volley from the edge of the area after the equally creative Patrik Berger – back from a groin injury – had set up the opportunity.
And Sheringham was only just off the mark on two other occasions when Alexei Smertin and the hard–working Steve Stone provided the spade–work.
The former Tottenham and Manchester United ace also stretched himself to provide openings for young strike partner Yakubu Ayegbini, but the unlucky Nigerian was twice wayward with his finishing after doing well to find the shooting positions.
It looked a let–off for Charlton when the nimble on–loan Russian Smertin had to hobble with a knee injury after less than half an hour, but it was sub Sherwood's set–piece that instigated the breakthrough for his former Spurs team–mate.
And it was only then that Charlton found a higher gear. Holland was only inches away from connecting with Stuart's waist–high cross with a diving header at the far post and Parker whistled a 30–yarder just inches over.
Parker and Sheringham had gone head–to–head, eyeball–to–eyeball over a minor incident in the first half and the Pompey captain was booked for a crude late challenge on his opponent – who made something of a meal of it – early in the second.
At least Parker showed some grit for the Addicks before boss Alan Curbishley could wait no longer to bring on the unpredictable di Canio as a substitute for Claus Jensen with 25 minutes still to go.
But it was the man who came on alongside the Italian, defender Jon Fortune, who made the impact.
With just 12 minutes left a long throw by Graham Stuart appeared to bounce off a stray arm and leave Fortune the ideal chance to stab home an unexpected equaliser.
He had already, after replacing Mark Fish, missed with an inviting headed opportunity and could have won it three minutes later when Pompey's miserable attempt at an offside trap left him unmarked – but with back to goal he put Parker's chip over the bar.
Portsmouth still had chances to win it through Yakubu and then Berger – but none of that mattered to Charlton when Bartlett, whose two goals crushed Wolves earlier this season, popped up to head in di Canio's corner right at the death.
Charlton Athletic 2
Fortune 77, Bartlett 90
Half-time: 1-0 Attendance: 20,106Reuse content