A stunning Anton Bryan strike three minutes into injury-time gave United all three points in a close contest against Crewe Alexandra.
Neither side was able to play smooth, passing football due to a bobbly pitch.
But the Reds did take the lead through skipper Corry Evans shortly after the hour.
However, Crewe pulled themselves back into the match with an equaliser on 81 minutes.
The Railwaymen, with Dario Gradi watching on the sidelines, looked to have gained a point, but then Bryan intervened.
His shot was beautifully struck and left Crewe stunned, and sent Paul McGuinness' men back to Manchester with all three points.
United: Zieler; Moffat, Strickland (Norwood 59), Wootton, Dudgeon (Stewart 59); Bryan, James, Drinkwater, C.Evans; Galbraith, Macheda.
Subs not used: Gill, Brandao, Curran.