Substitute Conor Chaplin nodded home a second-half equaliser as Pompey got out of jail with a 1-1 draw at Wigan Athletic.
Up against their former boss Paul Cook, the Blues could well have been put to the sword in a first half dominated by Wigan and might easily have found themselves 5-0 down at the break, instead of the 1-0 scoreline.
Wasteful finishing, some terrific Luke McGee goalkeeping and the woodwork somehow kept Pompey in the hunt as a glut of gilt-edged chances went begging for the home side.
With Ivan Toney’s ninth-minute strike the only goal to show for their dominance, Wigan paid the price in the second half as they were reduced to 10 men when Chey Dunkley was sent off for lashing out at Brett Pitman as the balance shifted in Pompey’s favour.
Chaplin, who had only been in the pitch for three minutes, then nodded home the leveller 14 minutes from time thanks to Brandon Haunstrup’s searching cross and might have even taken the lead if Adam May’s stinging low drive had found the bottom corner.
Gareth Evans was then also shown a red card with two minutes remaining for a second bookable offence as both sides finished with 10 men.
Neither side was able to find the winner as the shares were spoiled but Pompey will be well aware they dodged a bullet on this occasion and will be more than thankful for the point.
Pompey handed a debut to Dion Donohue as they started the game in a 4-2-3-1 formation with the new arrival taking his place on the left flank in the revamped Blues formation.
As he took his place on the bench, Cook was given a hostile reception from the travelling Pompey fans with apparently plenty still unhappy at the manner of his exit from the club in the summer so soon after leading the club to the League Two title.
But as his old club stumbled out of the blocks and struggled to find any kind of momentum or cohesion, his new club gained the early initiative as they sought to build on their flying start to the campaign.
Wigan didn’t have to wait long for the opener as they took an early lead through Toney and could easily have been 3-0 up inside 22 minutes.
Pompey’s defenders may be thankful they will not have to face too many strike partnerships as potent as Wigan’s as Gavin Massey squared for Toney in front of an empty net and a simple tap-in.
The same man had a chance almost as easy six minutes later and should have made it 2-0, only for McGee to spread himself well after the Pompey defence was carved open far too easily once again.
With both Gareth Evans and Brandon Haunstrup struggling to contain the assault down their flanks, Pompey were not helping themselves with some sloppy passing as they struggled to create anything, before Nick Powell rattled the Pompey post after some nifty footwork with McGee nowhere near it.
Toney somehow then failed to convert another low cross, with the post, a last-ditch tackle from Evans and some good fortune coming to Pompey’s rescue. McGee then enjoyed a slice of luck, pushing aside one lone-range effort from Powell, which skewed off his gloves and behind before he produced a fine flying stop to deny the same opponent moments later.
Quite how it was only 1-0 at half-time was anyone’s guess.
Chances were few and far between for Pompey despite an improved showing after the break, as Jamal Lowe narrowly failed to convert Haunstrup’s cross.
But the Blues were handed a real opportunity to claw their way back into the game just before the hour mark as centre-back Dunkley was shown a straight red card for needlessly lashing out at Brett Pitman as the duo tussled for the ball.
It meant Cook had to sacrifice the dangerous Toney and Pompey began to grow into the game with the numerical advantage, finally building some pressure on the Wigan goal.
In truth, their first genuine attempt on goal brought the equaliser as Haunstrup’s searching cross found Chaplin at the far post, who made no mistake with his downward header across the goalkeeper into the far corner.
Adam May then tested the Wigan keeper with a stinging low drive as Pompey chased a winner.
Although the numbers were evened up again with two minutes to go as Evans was sent off after being shown a second yellow card, honours were even.