#2 Mother Luck
An essential ingredient for success in life is good fortune, and football is not an exception. Call it grace, good fortune, or good old luck, the bottom line is that despite your best efforts, you need that extra bit of fortuitous circumstances to aid your case, and United had it in abundance on the night.
They were so poor for the majority of the match that they should have been blown away, but a combination of factors ensured they were still in with a shout right till the death of the match.
They had it when the post came to their rescue on two occasions to deny Paulo Dybala and Sami Khedira when De Gea had been well and truly beaten, while it was also good fortune which helped the ball deflect off Alex Sandro and into the back of the net when it could have gone anywhere else.
Ronaldo spared no punches to his former side when he said United did not do anything to deserve the victory, and while not taking anything away from their hard work to stay in the game, and while they undoubtedly created their own luck by converting their chances, it is hard to argue that fortune did not favor them.