Steve Hunt's glorious 89th minute shot on the turn won Brentford a place in the southern area quarter-finals of The LDV Vans Trophy.
Hunt struck just as golden goal extra time was looming to separate two well matched teams that had slugged out a 0-0 draw in a league game at Griffin Park two weeks before.
Plymouth had their moments and will count themselves unlucky not to of taken the lead ten minutes before Hunt's stunning strike when manager's son Blair Sturrock thumped Brian McGlinchey's left-wing cross against the bar.
For Brentford, Jay Tabb was always a threat, and might of won a penalty when he tangled with Stuart Malcolm.
Soon afterwards, Hunt was set up by Rowan Vine but spurned the chance, only to make amends in spectacular style as the clock was running out