Once the smoke from the errant flare had dissipated and the post-match grappling bout dispersed, the view was crystal clear.
During the final week of the campaign, Pompey require two wins.
Achieving that would ensure should either Barnsley or Luton fail to win on the final day, Kenny Jackett’s men will be promoted.
Tantalisingly, if both of the current top two do not register victory on Saturday, the Blues will be crowned League One champions.
Pompey’s challenge is unequivocally straightforward.
Following 44 matches and almost nine months, Championship ambition has arrived at this intriguing juncture.
An occasionally abrasive 1-1 draw at the Stadium of Light may have wrestled advantage away from their grasp, no longer do the Blues possess destiny within their own hands.
Suddenly, they are reliant on others, hoping for slip-ups elsewhere to inspire another potentially remarkable last round of fixtures.
Nonetheless, focus is now locked. A period of five days will determine whether automatic promotion can be accomplished.
A point shared with Sunderland on Saturday did little to assist either club in overhauling the second-placed Tykes, who are seeking an instant return following relegation.
Instead the power shifted to Daniel Stendel’s men, themselves trailing Blackpool for 25 minutes on Saturday before recovering composure to claim victory.
Such repercussions all but eliminated the Black Cats from the pursuit, while established a four-point gap between a Pompey side with two matches still to fulfil.
A win for either of the Stadium of Light combatants was essential, a blockbuster occasion attracting 41,129. Win or bust, undoubtedly. In each dressing room pre-match, a draw was deeply unpalatable.
However, a lifeline has been cast, particularly beneficial for Jackett’s troops.
Long-time leaders Luton’s 2-1 defeat at Burton suddenly throws up the alluring possibility of a second promotion spot to chase.
It represented an energising pick-me-up for the Fratton faithful come the final whistle to raise sagging spirits following a point which in any other circumstances would be warmly embraced.
The stuttering Hatters have now taken just five points from a possible 15, invoking memories of the meltdown which befell Doncaster in 2016-17.
Back then, Rovers ended the campaign with four-straight defeats, allowing Paul Cook’s Pompey to overtake them for the League Two crown on the final day.
Surely there could not be a repeat of such an occurrence two years later? Yet it remains on the table, a mouthwatering prospect to those chasing clubs.
This campaign is heading towards a remarkable finale, with no promotion spot settled heading into the last week, accompanied by the League One title yet to be claimed.
Encouragingly, all is not lost after all following that Sunderland outcome, and Jackett was indebted to Craig MacGillivray for ensuring his side retain interest.
The goalkeeper plucked from Shrewsbury’s bench has enjoyed an outstanding maiden Fratton Park campaign, an ever-present during this promotion push.
Already attracting sizeable interest during ongoing voting for The News/Sports Mail’s Player of the Season, the Scot weighed in with a momentous display to fend off the Black Cats.
The Blues appeared leggy during the second half on Saturday, certainly lacking thrust to transform the fixture into the required victory.
Instead, led by Nathan Thompson, Christian Burgess and Tom Naylor in particular, they defended like lions. Such bravery warranted reward.
Behind them was MacGillivray, a magnificent presence throughout. There could have been no disputing the identity of Pompey’s man of the match.
Not that his display should be allowed to misrepresent the match which unfolded. Sunderland hardly overran their visitors, while lacked a grandstand finish which perhaps the fixture should have yielded considering its importance.
Following the interval, Pompey may have lacked the necessary urgency required to have carved out a win, but neither were they relentlessly challenged in the manner posed by an impressive Burton in the previous away game.
Jackett himself rightly conceded his team hadn’t done enough to triumph, but there was the nagging feeling the hosts also didn’t sufficiently threaten consistently enough to earn three prized points.
Still, the Blues’ keeper was indisputably man of the match, a telling statistic and one no doubt followers of the Black Cats will dredge up to back belief they deserved more.
MacGillivray’s finest moments occurred during the first half, two instinctive saves conjured up which had his manager purring after the final whistle.
On five minutes, Aiden McGeady’s left-wing cross was met with a flying overhead kick from Lewis Morgan eight-yards out, which the keeper brilliantly pushed onto his post.
Later in the half, Luke O’Nien’s tempting cross from the right was met first time by a sliding Charlie Wyke at the far post, only for MacGillivray to somehow scramble back and block the goal-bound effort.
There were, of course, a number of other entries scattered throughout the match, much to Pompey’s relief.
The Blues, however, fell behind on nine minutes when Max Power’s free-kick from the right was met with a far-post header from Tom Flanagan.
On that occasion he got the better of Thompson and animosity between the pair would erupt at the final whistle during the shaking of hands, the Sunderland defender opting not to let go while weighing in with a few choice words.
It prompted a post-match skirmish between both sets of players, which saw one peace-making member of the Black Cats barged to the floor by Naylor amid the chaos.
It was Jamal Lowe, though, who found Pompey’s leveller on 24 minutes, taking his tally to 17 for the campaign.
Ronan Curtis, recalled in place of Gareth Evans, delivered a cross from the left which appeared to be heading out of play, only for Brett Pitman to hook it back from the byline.
There was Lee Brown with a powerful header which crashed against the crossbar, the ball generously falling to Lowe on the edge of the six-yard box to steer right-footed into the net.
Unfortunate scenes followed during the celebrations, emanating among the 3,222 travelling supporters, when a lit flare was dropped onto Sunderland supporters below.
Referee Craig Pawson delayed restarting the match, consulting both managers and stadium staff, before the Pompey culprit was removed by police.
An ugly incident and as needless as the scuffle played up at the final whistle.
Now onto a pivotal week – and Pompey’s task is abundantly clear.