The Iron drew first blood in the battle of the Championship strugglers when Chris Dagnall opened the scoring with a speculative low shot in the fourth minute.
North End were booed off at the break but responded with two goals in six second-half minutes through defenders Craig Morgan and Billy Jones to lead 2-1.
However, Michael O’Connor drew Scunthorpe level with a fine free-kick just minutes later and winger Woolford tapped home the winner with eight minutes remaining to leave Preston with just one home win all season.
Scunthorpe had failed to win any of their previous six games but they fully merited their victory and the boos that rang out at the final whistle left Ferguson in no doubt as to the challenge facing him.
The visitors were buoyed by the presence of West Ham striker Freddie Sears, who was handed his debut after he joined on a month’s loan.
The 20-year-old has struggled for regular first-team football at Upton Park but he was a menace throughout and his new side soon led when Dagnall collected possession and hit a low 20-yard shot which flew into the net off the inside of a post.
The hosts almost fashioned an immediate response when Paul Hayes played a one-two with on-loan Manchester United youngster Josh King and hit a low shot from 12 yards which drew a fine parried save from Iron goalkeeper Joe Murphy.
Sears then picked up possession 25 yards out, advanced towards goal and unleashed a fierce right-foot shot which was deflected out for a corner.
It was a reminder of Scunthorpe’s threat, even if Preston largely dominated possession, as Sears teased and tormented the visitors.
Preston youngster Danny Mayor scuffed a shot wide on the half hour but Sears’ pace was evident again eight minutes after the restart when he broke the offside trap and scampered clear of a static home defence.
Sears bore down on Andy Lonergan but he lacked conviction and the Preston goalkeeper smothered his effort before Michael Collins fired the rebound wide.
Chants of ‘Fergie, sort it out’ from restless home fans at least prompted a response from the hosts and in the 58th minute Morgan rose highest at the back post to head home a corner from substitute Paul Parry.
In the 64th minute, Preston led from another corner which was cleared by the visiting defence but fired back into the net by Jones.
The lead was short-lived as the spirited visitors equalised when O’Connor curled in a deep free-kick from the left-hand side of the penalty box and into the top right-hand corner.
However, the real drama was still to come as Sears fired against a post from close range with eight minutes remaining before Woolford swept home the rebound.