Pompey exited the FA Youth Cup at the hands of Bromley, despite Harry Anderson continuing his fine run of goalscoring form.
The striker hit his 17th of the season from close range at Fratton Park, only for Liam Vincent to quickly level.
And with the tie heading for extra-time, a crisp finish from Ben Krauhaus ensured the Londoners would progress to the third round.
The hosts were missing several regular players through injury and suspension, with Harvey Rew and Charlie Bell among those out of action.
But it was still Pompey – watched by first team manager Kenny Jackett and skipper Tom Naylor – who made the brighter start and Harry Jewitt-White had an effort blocked, before Seok Jae Lee’s shot was deflected behind.
And they took the lead midway through the first half, when the visitors made a mess of dealing with Harrison Brook’s cut-back.
The ball fell at the feet of ANDERSON and the prolific striker made no mistake from a few yards out, confidently slotting the ball past Ryan McCourt.
Conor Manderson was not being troubled at the other end, although made a regulation stop from Soul Kader’s header.
It was the Blues who were on top and looking more likely to add to the scoring, only for Bromley to then equalise.
A clearance from Issiaga Kaba was charged down by Vincent, with the left-back then firing into the net.
Pompey had a chance to restore their advantage, as Anderson did well to nod a deep cross from Alfie Bridgman on target and force McCourt into action.
But they became more ragged as the half drew to a conclusion and their opponents tried to take advantage.
Vincent tried his luck with a free-kick from just inside the Blues half that a back-pedalling Manderson had to tip over the bar.
And they continued to threaten as the clock ticked down, with the hosts perhaps relieved to hear the whistle blow.
Half Time: Pompey 1 Bromley 1
The Londoners then had the first chance when the action restarted, with Jeremiah Obembe hitting a fierce strike past the post.
And it took a brilliant save from Manderson to keep the scores level on 54 minutes, with the keeper denying Kader from point-blank range.
The Bromley winger went close again moments later, but a ball in from the right was just too high and he was unable to guide a header on target.
Pompey finally clicked into gear just before the hour mark and an attempt from Brook was deflected behind.
The resulting corner caused all sorts of problems for their opponents and an eventual header from Dan Cadman looped onto the roof of the net.
Then, following good work from Alfie Bridgman, Brook teased his way into space and hit a dangerous ball across goal that was agonisingly out of reach for any of his team-mates.
Pompey were starting to move through the gears, with both Brook and Kaba sending headers narrowly off target.
The game appeared to be drifting rather aimlessly, but Lee tried to liven things up with a crisp strike from outside the box that flew just over the top.
It looked like the tie would be heading for extra-time, only for Krauhaus to rifle the ball home late on to give Bromley the lead.
And Pompey were unable to find a leveller, as the visitors held on to book a trip to Swindon or Metropolitan Police in the third round.
Pompey (4-3-1-2): Manderson; Setters, Kaba, Cadman, Bridgman (Payce 90+3); Dawson, Jewitt-White, Dockerill; Lee; Brook, Anderson
Goals: Anderson 21
Subs not used: Steward, Chitambo, Simpson, Greenough
Bromley (4-4-2): McCourt; Motobaluti, Akaguougu, McCarthy, Vincent; Krauhaus, Smith, Ohembe, Kader; Fisher (Lewis 90), Aranganthan (Igbesoko 66)
Goals: Vincent 28, Krauhaus 87
Subs not used: Nicholas, Wilkinson, Reid-Newth, Cousins, Jackson
Referee: Peter Lowe