Jed Wallace afterwards took to Twitter to revel in a Pompey ‘smash and grab’.
Oxford United boss Michael Appleton was left shaking his newly-coiffured head in disbelief at the outcome.
Certainly the players’ Kassam Stadium exit in a convoy of vehicles was reminiscent of the Italian Job.
Although it turned out an overnight break-in had deprived them of their usual coach with its windows having been shattered in the depot.
Still, there was an overwhelming feeling of injustice among U’s followers at what they perceived as a criminal result.
They had grounds for complaint, no question about that.
In a tight, evenly-matched game, a draw for so long appeared to be the likely consequence.
Not that the Blues would have begrudged such a conclusion to their fourth league fixture of the campaign.
Appleton’s men had struck the post and had strong appeals for a penalty turned down during the first-half, Danny Hylton involved in both.
At one point James Dunne was perfectly positioned on the line to keep out a Nigel Atangana header and prevent what would have been a spectacular own goal.
Ricky Holmes had to be withdrawn at the interval before he was sent off, such was the testing time at right wing-back he endured against the impressive Junior Brown.
Granted, the visitors improved after the break but their destiny appeared to be a highly-satisfactory point on their travels.
Then in the 80th minute came the moment which broke the hearts of the Oxford faithful.
In the process Craig Westcarr’s goal demonstrated just why so many of the Fratton faithful regard this season as a potentially successful one.
Even with the campaign in its infancy, such instances on such occasions cannot help but suggest the team is equipped to go a long way.
It came from a Nicky Shorey cross from the left, agonisingly out of reach of Danny Hollands in the centre but Westcarr was there.
The forward bundled the ball home via what appeared to be his knee and shin, undoubtedly not pretty but wholly effective.
The away following of 2,136 in a crowd of 6,852 erupted at what had appeared to be an unlikely victory as Pompey made it four successive wins in all competitions.
In the process, they moved from fourth into second spot in League Two, with only Morecambe ahead in clearly early stages.
The last time they occupied a top-10 placing in a league table over the duration of a week was in December 2008.
Tony Adams was manager at that point, although he had been dismissed by the time they ended the campaign in 14th spot under Paul Hart.
Encouraging statistics but it was the very manner of Saturday’s victory which gives true cause for optimism over what lies ahead.
Hardly vintage Pompey glimpsed through previous victories over Peterborough, Northampton and Cambridge.
Nonetheless, the defence were resolute, Dunne once again outstanding and another three points captured – and on the road.
Not that Oxford were by far the superior side outrageously denied a victory, far from it.
The contest was a fascinating affair involving two sides attempting to play football but unable to break each other down.
Chances were few and far between, even during the Blues’ improved second-half showing when they began to retain possession.
In fact, it was Atangana and Miles Storey who had the game’s best opportunities in the opening 45 minutes.
Firstly, in the ninth minute a delightful pass from Holmes slipped down the right put Atangana clean through only to hammer his shot wide.
Then Dunne fed Storey down the left and the forward cut in and drove a shot against the legs of keeper George Long.
Glorious chances – but Awford’s men spent the final eight minutes of the half clinging on as the hosts piled on the pressure.
The closest they came during that period of concern was when Hylton had a shot blocked from a corner and then his follow-up effort struck the right-hand post.
Further drama unfolded when the same player appeared to have been caught by Westcarr inside the penalty area after wrong-footing him.
Oxford’s protests continued to referee Darren Bond at the half-time whistle seconds later but there was no reversal.
The interval saw Holmes replaced by Jed Wallace in the right wing-back role – a position Pompey’s reigning player of the season was clearly struggling to adapt to.
Having already been booked for a lunge on Brown, Holmes was given a final warning by the match official following another foul on the same player just before half-time.
With a red card a very real prospect, he was taken off to avoid a similar fate to Adam Webster two games earlier.
Replacement Wallace had found himself on the bench alongside Ryan Taylor in the two changes to the team which defeated Northampton, Danny Hollands and Storey earning recalls.
And it was the entrance of Wallace, followed by Taylor on 64 minutes, which turned the match in the Blues’ favour.
Awford spoke afterwards how the introduction of Taylor enabled his team to play higher up the pitch, in turn allowing Wallace and Shorey greater attacking impetus down the flanks.
Fitting then that Shorey created the matchwinner for Westcarr just 10 minutes from time.
Oxford still had the opportunity to haul themselves back on level terms, however, through the ever-dangerous Brown.
On 83 minutes the winger popped up on the left-hand side to produce an angled drive which Paul Jones brilliantly fingertipped around the far post.
Then approaching full-time he was presented with a free header from four yards out as the ball bounced around.
Inexplicably he headed over and then crumpled to the ground for treatment to ease his blushes for a dreadful miss.
But Pompey saw out the five minutes of time added on without any further alarm to emerge from a draw banker with a victory.
Perhaps not so much a smash and grab – more a pocket being picked before escaping down the A34.