The unleashing of September storms accompanied by the referee’s whistle prompted the sounding of the retreat.
Otherwise Pompey stood firm. Indestructible, committed and marvellously unflinching.
They ventured to Kingsmeadow prepared for a physical battle – and teeth were unmistakably bared during an often bruising encounter.
Much to the displeasure of the home support, it may be added, taking umbrage at the muscling manner delivered by the Blues.
The Dons’ Callum Kennedy was stretchered off following a sickening clash of heads with Oliver Hawkins, while a battered Paul Robinson took two blows to the skull before forced to accept his early exit.
This was a tough-teak Pompey, brimming with effort and desire on their pathway towards claiming a deserved 2-0 triumph.
Only upon the onset of thunder and lightning did Kenny Jackett’s men back down, albeit under instruction from match official Kevin Johnson.
The half-time flurry prompted the visiting players to be summoned indoors as they limbered up for the second half, briefly delaying the restart.
They soon returned to inflict their own damage on a Wimbledon side bullied on their own turf in the footballing scrap.
Not to decry the standard of football delivered by Pompey, of course. There was nothing brutish over their approach or actions while in possession.
Yet there was steel interwoven with the silk, delivering a perfect mixture to combat a trip to Kingsmeadow and yield the three points strived for.
Jackett afterwards branded it the ‘most comprehensive performance’ so far of his fledgling Fratton Park tenure.
Certainly it was gutsy and brimming with heart, a welcome response to the disappointment of the previous defeat to Rotherham.
Neal Ardley’s men couldn’t muster a single corner, nor attempt on goal, as the Blues’ restored back four weathered any pressure with impressive reassurance.
Soon the referee was cast as the arch villain, even drawing howls of derision from furious home elements within the press box.
And granted, the penalty which delivered the opening goal of the game in the 38th minute was a little soft. Brett Pitman’s tumble possessed a touch of melodrama.
Yet the final score represented a well-warranted outcome for Jackett’s men, in the process collecting a maiden away victory of the campaign.
For a manager seeking to apply his own stamp to the team he inherited, there are growing signs of difference, in terms of approach and personnel.
The evolution has become far more rapid than initially mooted by the former Wolves boss, yet matches such as Saturday fully justify the quickening of pace.
Of the line up for the opening day of the season, just three were included in the starting XI against Wimbledon – Luke McGee, Christian Burgess and Pitman.
Gareth Evans, back from suspension, didn’t even make the match-day 18, along with Danny Rose. Mainstays of the title-winning team now watching from the sidelines.
However, Kyle Bennett was back, occupying the bench having suffered a similar fate in the televised encounter against Rotherham.
Meanwhile, the wing-back system rolled out in that 1-0 defeat was dismantled, as Jackett reverted to the 4-2-3-1 formation for the trip to the Dons amid three changes.
Nathan Thompson was handed a full debut, coming in at right-back, while Damien McCrory was given his Blues bow to replace Brandon Haunstrup at left-back.
The final alteration involved Matty Kennedy, so eye-catching on his substitute appearance against the Millers, asked to start on the left of the attacking trio.
Thompson’s deep ball from the right towards Pitman prompted the Barry Fuller push which created the first-half penalty which the visitors gratefully benefitted from.
Obviously a more defensively-sound option than Evans, he added solidity and helped restrict danger man Andy Barcham to a generally quiet afternoon.
Elsewhere, Kennedy was again impressive, his direct nature in attack was off-set by a willingness to track back on occasions. He also provided the cross which led to the Blues’ second goal.
As for McCrory, his was a reliable presence, snuffing out any threat staggering in his direction, while willing to distribute the ball constructively down the left channel.
Yet it was Adam May who truly stood out as he continues to blossom during a continued first-team presence.
The teenager was at the hub of the 2-0 victory, demonstrating an insatiable desire to possess the ball.
There are those who have questioned his inclusion, some with stronger language than others, yet the teenager’s range of passing and work-rate is to be admired.
In addition, he almost netted a stunning goal in the 78th minute with a 35-yard lob which backpeddling keeper George Long did well to tip over the bar.
By that stage Pompey were nursing a 2-0 lead which they never looked in danger of surrendering against their hosts.
Pitman’s fourth goal of the season – and second from the spot – had put their noses in front from the 38th minute.
Then the skipper provoked an angry reaction from Robinson after an aerial challenge left the Dons man with a cut around his eye.
Moments later, a clash of heads between Hawkins and Callum Kennedy had home fans baying for a red card for the Pompey man.
Hawkins, with blood on his hands, had to be helped off and cut a groggy figure as he made his way to the dressing room at the interval. Kennedy, sadly, had to be stretchered off.
Neither reappeared, with Chaplin introduced for Hawkins – and doubling the lead within 50 minutes.
Kennedy’s cross from the left was not cleared by Anthony Hartigan and when Chaplin’s first shot was blocked by the keeper, he made no mistake with the second, squeezing home a right-foot finish.
As the game progressed, the Dons, having used all substitutes, were forced to see out the final 10 minutes with 10-men after Christian Burgess’ overhead kicked connected with the head of Robinson, who came off.
Unfortunate, but this truly was a full-blooded Pompey showing.