Wayne Rooney's injury time penalty sunk Sheffield United and put our United into the fourth round of the FA Cup.
This is not a game that will live long in the memory, but Louis van Gaal's side are in Monday's draw and that is surely the only thing that matters.
Sheffield United deserve credit for a committed and resolute defensive display that looked to have earned them a lucrative Bramall Lane replay only for the skipper to scupper their hopes and provide Van Gaal with a potential Mark Robins moment.
United had dominated throughout but were unable to find a way through the massed defensive ranks of the League One side but finally broke through in dramatic fashion thanks to Rooney's intervention from the spot.
The Blades had actually created the first opening of the match through Connor Sammon, whom forced a smart save from David de Gea but that proved to be the visitors only effort.
Sheffield stopper George Long dived at the feet of Rooney to keep out the striker, whilst the impressive Bastian Schweinsteiger had a penalty appeal waved away when he went down under a challenge from Jay McEvely.
United introduced the twin threats of Memphis and the returning Jesse Lingard after the break in place of Herrera and the disappointing Juan Mata with Anthony Martial moving up top alongside Rooney in a re-shuffled 4-4-2.
Matteo Darmian went close and Memphis fired an excellent effort narrowly wide as United finally upped the ante.
John Brayford's lunging blocked thwarted Anthony Martial when the young Frenchman looked poised to score before Chris Smalling miscued from the follow up.
United's concerns looked to have been confounded when a stretcher was called for Schweinsteiger but fortunately the German returned to his feet and soldiered on to the end with his injury not as bad as first feared.
To their credit, Van Gaal's side continued to press and, not in keeping with the rest of the match, a dramatic late twist was to come.
Memphis went down under a challenge from Dean Hammond and Rooney made no mistake from 12 yards to send the Reds through.
Overall team performance: 6/10
United Faithful Man of the Match: No stand out perfomer in Red, but Bastian Schweinsteiger was the best of a bad bunch with his diligence and distribution