With May and Hayes spurning numerous early first half chances, the visitors took a shock lead. Richard Butcher had put the visitors ahead after just nine minutes, when his scuffed volley skipped off the wet surface past Lillis in United's goal.
Scunthorpe stormed back into the ascendancy- with the left-back Marcus Williams seeing an effort go scooting just over the crossbar, before Ben May forced a decent save out of the visiting keeper.
After the break, Matt Sparrow saw his vicious 30 yard drive come back off the cross bar, and Jonothan Forte's low drive clipped the outside of the post.
As the game wore on, it looked unlikely that United were going to find a way through. However their dominance did pay off when they threw on Gary Hooper up front replacing the excellent Dave Mirfin. Every senior Scunthorpe striker was on the pitch, and Adkins' men got the stroke of luck they deserved.
They finally levelled in the 90th minute when Hayes headed home from Morris' corner, and he completed the late turnaround when he headed the ball into the net following a terrific save from goalkeeper Hoult.
There was still a dramatic last ditch attempt from County, as goalkeeper Hoult stormed up field only to miss the ball that flew up off the slippery surface. And he had another chance to salvage an extra 30 minutes from the resulting passage of play, but his header wasn't on target.