This stormy encounter, on and off the field, was into the sixth and final minute of injury time when Marc Richards bundled the ball home to give ten-man Vale a last gasp 2-1 victory and a winning start under new manager Dean Glover.
The goal sparked a pitch invasion from the Vale supporters behind the goal, but when the pitch was finally cleared there was only enough time for Shrewsbury to kick-off when the referee finally brought to an end this tempestuous local derby.
Struggling Vale, who had last their last six matches, took a 19th minute lead through Louis Dodds as high-flying Town conceded their first goal at home this term.
That looked to be enough to secure victory for Glover's men as the Vale Park side, who had six players booked and Lee Collins ordered off, entered the closing moments of the match still ahead.
But in the 89th minute substitute Michael Symes grabbed a leveller for the home side, which appeared to have snatched them a late point.
Then in the dying seconds Richards struck for Vale to secure them an unlikely win.
Despite some early Shrewsbury pressure it was Vale who made the breakthrough, Dodds finishing a sweeping move by driving home from 12 yards in the 19th minute.
For the remainder of the first half and throughout the second period Shrewsbury pushed hard for an equaliser, although the best chance of the second half fell to the visitors, when Ross Davidson blasted over from ten yards.
But Town's persistence finally paid off and they drew level when Symes netted with an angled drive after a Ben Davies effort had been deflected into his path.
Collins was then red-carded for a second bookable offence and the home side went all out for victory, only for Vale to breakaway at the death with Richards on hand to secure an extraordinary win.