They were under intense scrutiny, the spotlight fixed on uncharacteristic failings threatening to rip apart the seams of promotion aspirations.
Pompey’s defence has creaked and cracked alarmingly during its previous two league outings.
So it’s fitting Christian Burgess should break from the rearguard ranks to provide a crucial contribution at the other end of the pitch.
Paul Cook’s lynchpin at the back demonstrated his effectiveness in the opposition penalty area to inspire a rare away victory.
The fact his headed match-winner arrived on a birthday weekend with family and friends well represented in the Brisbane Road auditorium added to pertinence of the occasion.
Not quite villain to hero, there are plenty of culprits responsible for the recent worrying spate of defensive woes. Never was it a one-man show.
Yet newly-crowned 25-year-old Burgess, who remains the strongest of the centre-halves presently at Fratton Park, responded to such collective set-backs in perfect fashion.
Crucially, he also marshalled the back line to a first clean sheet in seven matches, in the process safely negotiating danger man Jay Simpson and a special day for new boss Alberto Cavasin.
Talk about an admirable reaction to the twin defensive debacles of Blackpool and Doncaster – Cook’s under-fire troops rose superbly to the challenge of Leyton Orient.
In the process, they indicated the futility of early dismissals of their credentials to depart League Two this season.
Pompey have their off-days, especially in the past month where Accrington has been another low to contrast to the wonderful Barnet showing.
They have also endured defensive fragility having initially recorded four clean sheets in their opening six league fixtures.
Yet they continue to possess an immense strength of character, in addition to a deep pool of ability which can never be disputed.
In the build-up to visiting Orient, Cook would have viewed victory and a clean sheet as an appropriate counterclaim to the criticism flung in the direction of his stuttering side in the aftermath of a Doncaster defeat.
And that is precisely what he got as the Blues collected a second win away from Fratton Park this season.
As close enough to a faultless day in football for any manager, particularly one attempting to mastermind promotion.
Make no mistake, this was no stylish victory produced by the Brisbane Road visitors, there was little flourish and it lacked polish.
In addition, the scoreline suggests it wasn’t entirely convincing against a team eager to impress a new manager appointed days earlier.
Yet Pompey were largely comfortable, certainly once in the lead never hinting at surrendering the advantage they thoroughly deserved during a controlled performance.
Nothing flash but a hard-working, composed showing from a side which never looked hassled and refused to let themselves be hurried.
Admittedly, the scoreline should have been in greater favour of Cook’s side, particularly during the opening 45 minutes.
Nonetheless, it was a performance of immense efficiency in which none of the contributions from those on show should be criticised.
Not least the ever-dividing Kyle Bennett, whose promotion back into the starting line-up had come off an encouraging Checkatrade Trophy outing earlier in the week.
Kal Naismith had started the previous three league fixtures, but on Saturday Bennett dislodged him to produce an eye-catching display against Orient.
For his lack of action this season, the winger has still managed to contribute three assists, thereby highlighting what he can bring to a side.
Certainly his positive approach was apparent at Brisbane Road, often tucking in from the wing to get closer to the action in attempts at creating opportunities.
The outcome may not have been an assist on this occasion, yet it was his best performance of a season which has been disappointingly low-key for the former Doncaster player.
Cook’s other change to his side was handing Amine Linganzi a first League Two start for the club.
The midfielder, who still operates on a month-by-month deal, had previously lined-up in all three of Pompey’s cup competitions this season.
Yet he replaced Danny Rose to partner Michael Doyle in the midfield engine room, supplying his brand of energy, height and physicality to the Blues’ play.
There was also the wasted opportunity of a header from Gary Robert’s ninth minute right-wing corner to give the visitors an early lead.
The Congo international, however, managed to steer his attempt from five yards out impossibly wide, much to the disbelief of those present.
Still, that error should not overshadow a good full debut from Linganzi, whose work ethic was admirable until replaced in the 66th minute by Rose.
Cook had identified his side required a little tinkering and they were changes which paid dividends with victory and a rise to fourth place in the table.
The Blues would have wondered how they had failed to break the deadlock during an entertaining first half in which both teams threatened.
Conor Chaplin’s clever glancing finish from Enda Stevens’ left-wing cross appeared to have handed the visitors the lead on four minutes – only to be ruled out for offside.
At the other end, Yvan Erichot had strong appeals for a penalty waved away following Burgess’ challenge, albeit his rolling around on the floor needlessly screaming injury was over the top.
Pompey also thought they had won a spot-kick when Bennett went down under a lazy challenge from Gavin Massey in the 29th minute, only for a yellow card for diving to be produced.
Throw in Linganzi’s miss and Chaplin seeing Alex Cisak save his shot when a goal beckoned and the first half should have yielded more.
However, on 57 minutes, Pompey finally achieved their breakthough when Carl Baker’s corner from the left was headed home by Burgess.
A rare set-piece goal from the Blues, achieved by a player usually responsible for preventing them.
It was Burgess’ day, however, with a man-of-the-match showing coupled with a welcome clean sheet.
And the optimism returns.