Thomas O'Ware broke Peterhead hearts with a late winner at Balmoor to give Morton a 2-1 victory.
With the match deep in stoppage time the defender smashed home from 12 yards, following a scramble in the box, after what had been a close tussle between the two teams throughout.
Morton took the lead just after the interval when defender Stefan Milojevic found the top corner following a pinpoint cross by Joe McKee.
But the Serbian went from hero to villain, fouling Andrew Rodgers in the box on 66 minutes, before Rory McAllister converted the resultant penalty for the equaliser.
With time ticking away, goalscorer McAllister saw red for two late bookings before O'Ware made his game-changing intervention at the death.