Conor Chaplin bagged a brace as Pompey got their promotion challenge back on track by beating Leyton Orient.
It was a display of almost total dominance by the Blues and the margin of victory probably should have been greater.
Chaplin saw a penalty saved, but quickly put that out of his mind to open the scoring, only for Gavin Massey to grab an impressive leveller.
There was to be no shock outcome, however, as Chaplin grabbed his second of the afternoon – and seventh of the season – early in the second half.
Paul Cook made one change from the side that were beaten at table-topping Doncaster nine days earlier.
That saw Chaplin replace Kyle Bennett, as the hosts switched to a more traditional 4-4-2 system.
There were plenty of familiar faces in the opposition line-up, with former Blues Alex Cisak, Nigel Atangana and Paul McCallum all selected.
Both sets of fans held a minute’s applause before kick-off in memory of former Pompey and Orient defender Paul Went, as well as ex-England boss Graham Taylor.
On the pitch it was a totally dominant first half display from the hosts, who set about attacking their struggling opponents straight from kick-off.
Chaplin could not quite get a touch to Kal Naismith’s clever free-kick after nipping in between a couple of defenders.
Tom Parkes then made a mess of trying to clear Carl Baker’s cross and Cisak had to intervene to stop the ball dipping under the crossbar.
Naismith soon played a neat one-two with Michael Smith and burst into the box, only to then fire over the top.
The hosts had an even better chance to break the deadlock on 22 minutes when Sammy Moore tripped Enda Stevens just inside the box.
Referee Brett Hutxtable pointed to the spot, but Cisak guessed the right way to palm Chaplin’s shot wide – the fifth penalty that Pompey have missed this season.
It was only a brief respite for the beleaguered visitors, however, as CHAPLIN made amends just seconds later by arriving at the far post to turn home Baker’s low cross.
The Blues immediately set about trying to add to their lead and Baker sent an effort curling narrowly past the post.
And Smith was unlucky not to add his name to the scoresheet when he met Naismith’s corner, only to see his header cleared from the line by Parkes.
David Forde might as well have been sat in the Fratton End such was Pompey’s dominance in the early stages.
But his first involvement was to pick the ball out of the net, as Orient levelled with their maiden chance on 38 minutes.
Not that the keeper could have done much to stop a stunning strike from Massey that flew into the top corner.
And the action was soon back down the other end of the pitch, with Stevens’ cut-back going behind three of his waiting team-mates in the box.
There was still time for one more chance in stoppage-time, with Teddy Mezague making a brilliant block to deny Baker before Naismith drove the loose ball wide.
Half Time: Pompey 1 Leyton Orient 1
There was a surprise switch at the start of the second half, with Jamal Lowe introduced in place of Gareth Evans – who had picked up an injury before the break – to make his Blues debut.
That saw Baker drop to right-back, but it did not stop his attacking intent as he soon provided the assist for a second Pompey goal.
It was a fine cross in from the right and CHAPLIN showed his usual poaching instincts to arrive and head the hosts back into the lead.
There might have been another soon after when Cisak fumbled Stevens’ low cross, but the keeper grabbed the loose ball before Smith could pounce.
Orient were unsurprisingly showing more ambition than prior to the interval, but it was still the Blues controlling possession as the half progressed.
Naismith, in particular, was looking full of confidence, showcasing some silky skills to jink his way past challenges.
But there was almost a disaster for Pompey on 66 minutes when Christian Burgess did not spot Forde coming to collect the ball and headed narrowly past his own post.
It was soon back to normal, though, and only a slight deflection prevented Smith from turning in Naismith’s free-kick.
Amine Linganzi replaced the Scottish winger on 76 minutes, as Cook looked to inject more steel into the midfield.
But that did not mean the Blues were looking to sit on their lead and a sliding Smith was agonisingly close to reaching Chaplin’s centre.
Stevens then surged into the box from wide on the left and sent a powerful effort fizzing past the post.
Chaplin received a standing ovation as he left the pitch to be replaced by Bennett for the closing stages.
And it was a deserved reception for the diminutive striker, as Pompey saw out the final few minutes to secure a valuable victory.
Pompey (4-4-2): Forde; Evans (Lowe 46), Burgess, Clarke, Stevens; Baker, Rose, Doyle (c), Naismith (Linganzi 76); Smith, Chaplin (Bennett 87)
Goals: Chaplin 23, 47
Subs not used: O’Brien, T.Davies, Roberts, Hunt
Leyton Orient (5-1-2-1-1): Cisak; Judd, Hunt (c), Mezague, Parkes, Semedo (Palmer 89); Moore (Bowery 69); Atangana, Collins; Massey; McCallum
Goals: Massey 38
Subs not used: Sargeant, Pollock, Kennedy, Nnomo, Koroma
Referee: Brett Huxtable
Attendance: 16,564 (607 away fans)