Following two defeats against Liverpool and Fulham. Three players suspended. Many more injured. Second in the league after Liverpool's victory yesterday, the last thing Manchester United wanted to see was a pacey Aston Villa side.
With a makeshift back line of Neville, O'Shea, Evans, and Evra, the home side's defence lacked pace with the absence of Ferdinand, Brown, or Rafael. With this in mind, Agbonlahor, Milner and Young must have been licking their lips in anticipation of beating the World Champions in their own backyard.
The odds were even more stacked against Manchester upfront, with Rooney and Scholes suspended and Berbatov injured, United's midfield and front line looked weak at the start of play.
The game started out an even one with Villa having the best chance of the opening exchanges, with John Carew's header cleared off the line by Scottish midfielder Darren Fletcher.
Soon after this, United got their first real chance of the game. With Friedel seemingly in control of the situation in the Villa box, Milner inexplicably toe-poked the ball toward goal, leaving Friedel no choice but to fall on the ball and give away the back pass.
After referee Mike Riley marched the wall back and encroachment from the wall which earned Milner a booking, Ryan Giggs and Cristano Ronaldo stood over the indirect free-kick. Giggs nudged it, then Ronaldo finished it. A smart finish curled over Nicky Shorey at the back post.
This gave United a boost that the needed badly after a poor run before the international break. With a goal in the back united pressed on, until a ball over the top to Barry on the right wing caught the Red Devils off guard.
The England international smartly wriggled away from Evans and Evra before a precise cross found John Carew. The big Norwegian forward made no mistake in beating Van der Sar from 10 yards with a header at the back post.
The equaliser for Aston Villa prompted a change from Sir Alex Ferguson. Skipper Gary Neville, who started at centre-half, was switched to right back with John O'Shea moving inside one place.
Both goals coming in the first half, this one was heating up to be a lively game.
Young then twisted and turned against the veteran full-back, but shot straight at Van der Sar.
Ronaldo had United's best chance with a glancing header, but he could also only find the keeper's waiting arms.
Halftime drew nearer and both sides looked content on getting to the break level, and that's how it was.
The second half started with United getting the better of what was again a tight affair. On the hour mark, with United on the attack and plenty of bodies committed forward, Ronaldo gave the ball away cheaply on the edge of the Villa box.
With both Neville and Ronaldo on the attack, Petrov charged into the space on the left before playing Carew away down the left. Carew put in the telling cross, this time with Agbonlahor on the end of it to head past the onrushing Van der Sar.
Agbonlahor needed treatment after the goal, but i'm sure he didn't mind, as he had just put his side 2-1 up at Old Trafford. How United must have been wishing for just one of Ferdinand or Vidic.
With Ronaldo petulantly shaking his head after the goal, he seemed to forget that it was he who gave the ball away which led to the goal, the Champions needed a leader to lift them.
That leader came from an unlikely source. Johnny Evans put in a battling performance with some last-ditch clearances and a couple of attacking headers that came close. This along with Tevez's willingness to run seemed to lift the United crowd.
United manager Sir Alex Ferguson decided it was time to take a gamble. He removed the ineffectual Nani and replaced him with a 17-year-old Italian striker. Federico Macheda.
At first Macheda looked nervy and struggled to get into the game, but what was to follow was nothing short of a fantasy debut.
With United attacking, pouring men forward in search of an equaliser it always looked likely that United would concede a third. But as the game entered the final 10 minutes, Ronaldo appeared.
Having being largely ineffectual since scoring, the Portuguese winger found space on the edge of the box and unleashed a low left-foot shot. Friedel could only look an as the ball rolled past his outstretched left arm.
United back level there was now only one winner. The crowd behind them, the team lifted the home side pushed on.
Carlos Tevez, who had been in Bolivia in the week with his well-beaten Argentina side, had come to the end of his game. 17-year-old Danny Welbeck replaced him.
With two 17-year-old forwards on the pitch, United were surely hoping rather than expecting one of them to come good for them
Only moments after being on the pitch, the ball found its way to Welbeck inside the Villa box. He sprung clear of the defence but could not beat the big American Brad Friedel in the Villa goal.
Villa must have thought that they had seen out the last of the home side's threat.
The fourth officials board gave United renewed hope, showing five minutes.
With another United attack, Macheda got himself one on one with Luke Young. The ball was played into his feet, and with a clever first touch that sent Young the wrong way the striker curled the ball past a full stretch Friedel to see the ball fly into the far corner.
Scenes of elation were to follow at Old Trafford, as they were able to keep the ball comfortably for the closing minutes.
After Liverpool's injury-time winner yesterday at Fulham, sent them back to the top of after several weeks in second, Manchester United, missing many stars, managed to return the favour to Liverpool by overtaking them with a last-minute winner.