Posh, desperate to end a League Two losing streak of eight consecutive matches, took the game by the scruff of the neck when Peter Gain broke the deadlock on 71 minutes.
But Sturrock shattered their dreams just a minute after being sent on by his father, Swindon boss Paul Sturrock.
Ferguson resisted the temptation to play in his first game in front of home fans by sticking to the formation that gave a much improved weekend showing at Lincoln, although still failing to end that dire losing sequence stretching back to December 16.
With five in midfield, Posh tried to attack promotion chasing Swindon with skipper Micah Hyde pulling the strings.
Posh created early chances with Aaron McLean failing to hit the target before George Boyd's strong cross was well gathered by visiting goalkeeper Phil Smith.
Swindon top-scorer Christian Roberts brought the best from Posh's Mark Tyler with a snapshot, but Boyd should have broken the deadlock after being put in by Adam Newton's shrewd cross only to fire well wide of Smith's left-hand post.
Posh carried the game to Swindon after the break with Josh Low crossing to the far post where Newton's header was palmed out by Smith but only to Richard Butcher whose effort was blocked by Swindon skipper Ady Williams.
Butcher had to be rescued by Tyler after he twice lost possession to let in Ricky Shakes and Lee Peacock before the long serving keeper snatched the ball out of the path of substitute Lucas Jutkiewicz who had stormed through the middle.
Peter Gain broke the deadlock by drilling a low left-footed shot inside Smith's left-hand post after gathering a throw by Low, but Posh's joy was stifled when Sturrock created a chance out of nothing to fire home from 15 yards.