"We lost a terribly soft goal for the first one and that gave them a platform to build on," admitted Sir Alex on MUTV.
"It was important for them and it was a bad one for us. It was an uphill fight after that, and then the second goal right after half-time (scored by Bobby Zamora) killed the game. That was a killer for us. We didn't anticipate that."
Coming just seconds after the restart, Zamora's strike made it difficult to assess what Sir Alex might have said to his team at half-time in tactical terms. With United now trailing by two goals, the boss felt compelled to change his personnel - sending on Dimitar Berbatov and Fabio for midfielder Darron Gibson and the inexperienced Ritchie De Laet.
"When we went further behind, we had to change and go to a back four - with young Fabio at right-back, and Darren Fletcher and Michael Carrick at centre-backs - because we had to chase the game. The referee made a poor decision for the third goal (it came from a free-kick) but by then I think it was very difficult for us. We couldn’t get behind Fulham at all, they defended very well, they were organised.... it was a difficult day for us really."
Despite the team's travails, the United fans remained vocal throughout the game. Sir Alex said, "They were fantastic, absolutely brilliant. They brought a bit of Christmas cheer."