Kamikaze Pompey opted for the self-destruct button to ensure Doncaster Rovers maintained their recent dominance over them.
Darren Ferguson’s team were one of two sides who completed the double over the Blues during the League Two title-winning campaign.
And they once again tasted victory last night during an eventful Keepmoat Stadium fixture in which Pompey contributed significantly to their own downfall.
A calamitous opening six minutes saw the hosts race into a two-goal lead, leaving the visitors with mountainous terrain to scale.
Liam Mandeville and Christian Burgess’ own goal were responsible as the ragged Blues defence were savagely torn apart so early into the action.
Kenny Jackett was required to be ruthless at the interval and hauled off skipper for the night Gareth Evans and Doncaster old-boy Kyle Bennett for Conor Chaplin and Jamal Lowe.
The double switch lifted the side and the deficit was reduced on 54 minutes through the home side’s generosity.
Mathieu Baudry’s backpass went under the foot of keeper Ian Lawlor for a remarkable own goal.
Substitute Chaplin, making his 100th appearance for the club, had also struck the post from a free-kick.
But just as Pompey were threatening to level terms, Dion Donohue thoughtlessly kicked out at Donny sub Niall Mason to reduce them to 10 men for the final 23 minutes.
In the process, it devastated hopes of grabbing a point, and following three successive victories the Blues slipped to a 2-1 defeat.
Jackett made just the one change to the side who beat MK Dons so impressively on Saturday.
Lowe had missed training during the build up to attend the birth of his daughter.
The winger arrived only hours before kick-off, travelling from the south coast with chief executive Mark Catlin.
And that prompted a recall for Evans on the right-hand side of the attacking three.
Lowe dropped to a bench which included Chaplin, who was fit-again following a hamstring problem.
With Drew Talbot missing through a groin problem collected in training on Sunday, the striker took his substitute spot at the Keepmoat Stadium.
Milan Lalkovic also travelled with the squad, although there was no place for him in the match-day 18 following Lowe’s attendance.
However, Jackett was still missing Brett Pitman, Damien McCrory, Jack Whatmough, Curtis Main and Adam May through injury.
The Blues began the match positively, yet found themselves behind after just three minutes.
Tommy Rowe surged forward and pushed the ball out to the right, where Rodney Kongolo drove in a cross.
And there was Mandeville from six yards out to fire home a shot which was deflected past Luke McGee.
The visitors slipped even further behind just two minutes later following Harry Toffolo’s corner from the left.
That was met at the far post by Rowe, with Burgess’ lunge then diverting the ball past his own keeper.
Pompey were all over the place and on eight minutes another Toffolo flag-kick was met by a Joe Wright header at the far post which bounced just wide.
There was an immediate response from Jackett’s men, with Evans fed down the right.
His precise cross was headed back by Oli Hawkins, but Bennett acrobatically lifted the ball over the bar.
On 22 minutes the Blues came agonisingly close to reducing the deficit following a Matty Kennedy free-kick down the left.
Burgess rose highest at the far post to plant an angled header goalwards, only for the ball to be nodded off the line by Wright.
Steadily, Pompey managed to wrestle more possession, but were rarely looking capable of threatening the home goal.
When the whistle sounded for half-time, they were still two goals behind following their awful opening.
Unsurprisingly, Jackett made two substitutions at the interval, with Chaplin and Lowe replacing Bennett and Evans.
In the 50th minute, Hawkins won a free-kick right on the edge of the box – and on this occasion the left-hand post came to Rovers’ rescue.
Chaplin took the dead ball and flighted a left-footed shot over the wall, only for it to smack the woodwork with Lawlor beaten.
Yet on 54 minutes it was 2-1 through a remarkable own goal.
Baudry turned to deliver a backpass from outside the penalty area. But the path of the ball was misjudged by Lawlor and he let it go under his right foot to find the net, despite a desperate late dive by the keeper.
It was a dreadful mistake and suddenly the visitors were back in the game and striving for at least a point.
The Blues were buoyant and when Kennedy’s backheel released Donohue, the left-back’s cross was met with a Chaplin snapshot which veered just past the post.
However, just as Pompey were offering encouragement, they ground to a halt through the sending off of Donohue on 69 minutes.
The full-back played the ball inside to Kennedy and kicked out at substitute Mason in the process – an act witnessed by the vocal Doncaster bench.
It appeared the fourth official had also observed what they were appealing for and referee Martin Coy showed Donohue the red card.
The ensuing reshuffle saw Kennedy drop into left-back to complete the back four, with Chaplin moving over to the left flank.
And it would take the arrival of four minutes of time added on for the visitors to next threaten, when Lawlor brilliantly tipped over Lowe’s header from Kennedy’s left-wing cross.
That was their last chance to grasp something from the game.
So when the whistle sounded for full-time and signalled another League One defeat, the Blues could blame nobody but themselves following a night of many failings.