Sir Alex Ferguson's side make it through the group stage with two games to spare after an interrupted 3-1 win over Braga.
Champions League: Manchester United surge into knockout stage despite Braga power failure
Manchester United's qualification for the Champions League knockout stages with two games to spare is the perfect response to last season's disappointing performance, believes Mike Phelan, the assistant manager.
Sir Alex Ferguson's side failed to make it out of their group in 2011-12, but sealed top spot and a place in the knockout phase after just four matches after coming from behind to beat Braga 3-1 at the Estadio AXA,
The result means Manchester United can go into their final two group fixtures knowing they cannot be caught by Cluj or Galatasaray, both on four points, or Braga, who have three.
"Our intention this year was to get into [the knockout phase] very quickly," said Phelan afterwards.
"We were disappointing last year - the players and staff knew that, and I think the supporters wanted a reaction to that.
"I think it was really important that we got into it quickly and we have done that - four games gone and we are more than happy with it."
As they have on several occasions this season - including two of their previous three Group H games - United conceded the opening goal, which came four minutes into the second half.
Custodio collided with Jonny Evans in the box and Alan, scorer of Braga's two goals when they went 2-0 up at Old Trafford last month before eventually being beaten 3-2, smashed home the resulting penalty.
A side showing six changes from the weekend's English Premier League win over Arsenal had struggled to get into the contest up to that point and not long after Alan's goal, a power cut which saw some of the floodlights go out led to a break in play.
The visitors emerged for the resumption around 15 minutes later with Rio Ferdinand on for Evans, and after Robin Van Persie and Rafael also entered the fray for Danny Welbeck and Nani, the tide turned.
Van Persie expertly guided the ball from outside the box over stranded goalkeeper Beto to equalise, before a penalty from Wayne Rooney - who had missed one against Arsenal - and a late Javier Hernandez effort wrapped up United's win.
Phelan admitted the way things had turned out had been surprising and suggested the power cut hold-up had been to United's advantage.
"It is a little bit surprising that we have scored three goals here tonight," Phelan said.
"In the first half we were not really doing anything in the game other than keeping possession of the ball.
"Possibly with the way the evening panned out - with the lights going out and the heavy rain, and then us having to make a quick substitution, bringing Rio Ferdinand on - that changed things for us, with the tempo of our game going up.
"Robin was instrumental in getting us further up the field. We played a little bit more in behind their midfield once Robin came on, and obviously he took his goal really well.
"It fell to him in a very good position on his left foot, he saw the goalkeeper probably trying to get to the ball a bit too quickly, and managed to hit it into the back of the net."
Jose Peseiro, the Braga coach, felt the final score line had been harsh on his team and praised them for their efforts.
"I didn't see a clear opportunity for Manchester United until 80 minutes," Peseiro said.
"I think they played well after the lights went off and we made some mistakes, which will happen against Manchester United.
"But in this game I think my team was fantastic - better than at Old Trafford. My team did not deserve this result, in my opinion."
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