Pompey’s impressive start to the season continued as they took all three points away from Bristol Rovers.
Gareth Evans headed home midway through the first half as the Blues dominated the opening part of the game.
But the hosts improved after the interval and forced an Aaron McCarey own-goal during a period of pressure.
That kicked the visitors back into life, however, and Jayden Stockley – who was not even supposed to be starting – grabbed the winner.
Paul Cook made three enforced changes from the side that drew at Oxford the previous week.
Loan signing McCarey came straight into the team in place of injured keeper Paul Jones.
There were also spaces for Danny Hollands and Adam Barton in midfield, with Nigel Atangana (back) and Michael Doyle (suspended) both out.
But another switch had to be made once the sides had been named – with Adam McGurk picking up a knock in the warm-up and being replaced by Stockley.
After a slow start to proceedings, it was Pompey who soon started to control possession and trouble their opponents.
Their first decent opening arrived on 15 minutes when Evans charged into the box and shot with the outside of his boot, only to be denied by onrushing Rovers keeper Lee Nicholls.
Tom Lockyer then had to race across the box and clear the danger when Stockley quickly flicked Evans’ pass on to Conor Chaplin.
And it was Chaplin who should have broken the deadlock moments later, with the teenager somehow heading Kyle Bennett’s cross wide from just a couple of yards out.
The Blues continued to torment their hosts and their pressure finally paid off on 29 minutes.
It was the impressive pairing of Bennett and EVANS who combined to open the scoring, with the latter meeting the former’s cross and guiding a header into the corner.
Debutant McCarey had been a virtual bystander for much of the half, but was called into action twice before the interval.
First he had to adjust his feet quickly to stop Lee Brown’s deflected cross from sneaking in at the near post.
Then he made a smart stop to deny Jermaine Easter after Christian Burgess’ unfortunate slip had gifted an opening to the Rovers striker.
It was the visitors who had the final say, however, with a quick counter-attack, but Evans could only divert Chaplin’s pass straight at Nicholls.
Bristol Rovers 0
Pompey had been in almost total control before the break, but the hosts found themselves level early in the second half.
They enjoyed a spell of pressure before grabbing the equaliser – although there was a hint of fortune about the goal.
The Blues failed to deal with a cross and although Easter’s shot came back off the bar, the ball ricocheted off McCarey and into the net.
Pompey were struggling to find any sort of rhythm and they almost fell behind on 56 minutes when Easter’s long-range drive cannoned back off the post.
But the hosts then had two penalty appeals from skipper Ben Davies and Chaplin turned down, with referee Jeremy Simpson deciding the latter had dived and brandishing a yellow card.
Cook made his first substitution on 68 minutes, with Gary Roberts – who has been suffering with an ankle problem – replacing Chaplin.
But it was Bennett who immediately had a chance to restore the Blues’ advantage when he surged down the right and into the box, only to fire wide when a pass to Stockley was arguably the better option.
STOCKLEY soon had his chance to score, however, and took it when he poked home a fine Davies cross to end a patient passing move from Pompey.
Rovers tried to find another leveller, but the Blues were looking dangerous on the break, with Cook opting to bring on Kal Naismith and Matt Tubbs rather than shut up shop.
That attacking mentality almost paid off on 82 minutes when Roberts played a clever pass to Evans, but Nicholls kept out his fierce drive.
The hosts tried desperately to get the ball forward in search of a last-gasp point, but Pompey held firm to go top of the League Two table.
Bristol Rovers (3-5-2): Nicholls; J.Clarke (Gosling 46), Lockyer, Parkes; Leadbitter, Sinclair, Lines (c), O.Clarke (Bodin 46), Brown; Harrison, Easter (Taylor 72)
Goals: McCarey 48 (og)
Booked: Lines, Gosling, Lockyer
Subs not used: Mildenhall, McChrystal, Montano, Mansell
Pompey (4-2-3-1): McCarey; Davies (c), Burgess, Clarke, Stevens; Barton, Hollands; Evans, Chaplin (Roberts 68), Bennett (Naismith 74); Stockley (Tubbs 79)
Goals: Evans 29, Stockley 71
Booked: Stockley, Chaplin
Subs not used: Bass, Webster, May
Referee: Jeremy Simpson
Attendance: 8,555 (1,188 Pompey fans)
Jayden Stockley scored deep into stoppage-time to complete a remarkable comeback and secure a point for Pompey against Morecambe.
The visitors rocked their hosts with first half goals from Tom Barkhuizen, Alan Goodall and Andy Fleming.
But a couple of fine Gary Roberts strikes either side of the interval brought the Blues right back into the game.
Enda Stevens’ dismissal for two bookable offences failed to halt their attacking intent as Pompey poured forward at every opportunity.
And their perseverance was rewarded in the fifth minute of stoppage-time when Stockley dived to head home the equaliser.
Paul Cook named an unchanged side, as he elected to use the same starting 11 for a fourth successive league match.
That meant Ben Davies – who went off at Crawley during the week – had sufficiently recovered from a hamstring injury to take his place at right-back.
Pompey looked to attack straight from kick-off and a neat move ended with Nigel Atangana firing over in the opening seconds.
Stevens then skipped into the box before Adam Dugdale came across to thwart him, before Matt Tubbs could not quite guide a corner on target.
The hosts were dominating possession yet again, but were caught with a counter-attacking sucker punch on 11 minutes.
Michael Doyle slipped and Davies’ clearance ricocheted into Barkhuizen’s path, with the wide-man smashing a shot past the helpless Brian Murphy.
The goal seemed to rock the Blues and a period of sluggish play ensued, with Cook’s men guilty of far too many misplaced passes.
However, Pompey started to move through the gears again and Roberts guided Stevens’ pass narrowly past the post.
But the Shrimps soon doubled their advantage after Christian Burgess had been booked for a foul on Aaron Wildig.
A diving Murphy was able to palm Jamie Devitt’s free-kick behind, but the Morecambe midfielder’s resulting corner was headed home by Goodall.
Wildig then tried to catch Murphy out with a neat chip that dipped onto the crossbar before the same played dragged a shot wide.
Shrimps keeper Barry Roche was booked for taking too long over a goal-kick on 36 minutes, although the visitors arguably did not need to waste time as they continued to open the Blues up on the break.
And they soon went three goals ahead when Fleming arrived at the far post to steer home Devitt’s cross.
Pompey looked all at sea, but there was a glimmer of hope late in the half when ROBERTS was brought down on the edge of the box and picked himself up to curl home an impressive free-kick.
Davies had a chance for the Blues soon after the restart, with a close-range volley that hit Dugdale in the face and flew safe.
There was then danger at the other end when Matt Clarke under-hit a pass, but the teenage centre-back recovered well to win the ball back.
And Pompey were soon back on the attack and Tubbs rose to glance Kyle Bennett’s cross inches wide, although it would not have counted as the linesman’s flag was raised.
The hosts were not having any trouble getting hold of the ball, but Roche was not being overly tested between the sticks.
They did reduce the deficit further thanks to another moments of magic from ROBERTS on 65 minutes, however.
The midfielder picked the ball up and deceived a couple of defenders with his footwork before curling a shot into the bottom corner.
Cook freshened up his front line with a substitution on 70 minutes, as Tubbs made way for aStockley.
But the Blues were soon reduced to 10 men when Stevens caught Aaron McGowan and was shown his second yellow card – and a subsequent red – by referee Roger East.
Adam Webster was brought on for Davies as Pompey switched to playing with three central defenders.
They were leaving plenty of men forward, safe in the knowledge that Morecambe were happy to sit back and soak up pressure.
Cook made his final change on 80 minutes as Adam McGurk replaced Gareth Evans and immediately received a chance to level when he rose to head Bennett’s cross narrowly wide.
Bennet then had an opportunity of his own, cutting inside and drilling in a shot that Roche did well to punch clear.
Morecambe were hanging on and Roche pushed Clarke’s header over before keeping out a Stockley drive.
And Webster missed a great opportunity after being left unchallenged in the box, only to head over.
The defender then saw his penalty claims for a handball waved away as Pompey continued to pour forward.
And just when it looked like time would run out on them, Webster delivered a perfect cross for STOCKLEY to convert with a diving header.
Pompey (4-2-3-1): Murphy; Davies (Webster 74), Burgess, Clarke, Stevens; Atangana, Doyle (c); Evans (McGurk 79), Roberts, Bennett; Tubbs (Stockley 70)
Goals: Roberts 42, 65, Stockley 90+5
Sent off: Stevens (two yellow cards)
Subs not used: Jones, Haunstrup, Hollands, Chaplin
Morecambe (4-2-3-1): Roche; Beeley (c), Dugdale, Parrish, Wilson; Fleming, Goodall (Kenyon 47); Devitt, Wildig, Barkhuizen (Molyneux 56); Miller (McGowan 68)
Goals: Barkhuizen 11, Goodall 25, Fleming 38
Booked: Fleming, Roche, Beeley, Wildig
Subs not used: Thompson, Bailey, Ryan, Mullin
Referee: Roger East
Attendance: 16,052 (69 away fans)
Loan : AFC Bournemouth – Portsmouth