Much of their season has been characterised by a knack of grinding out results without playing particularly well but the performance over both legs of a 3-1 aggregate victory against the London side was all about style and class.
Manager Sir Alex Ferguson has been quick to point out that this season is very different to 1999 because of the injuries they have suffered but his players have recovered just in time for the run-in and returned with a new spark.
"I think we've hit our form," said Ferguson after Tuesday's 2-1 victory at Old Trafford. "I don't think there's any doubt about that. You've seen it in the second half at West Ham (a 4-2 win after being 2-0 down at half-time) and the (first leg) performance at Chelsea, plus the performance tonight."
Ferdinand, who started limping early in Tuesday's 2-1 win at old trafford but battled on, was just one of several key figures who were outstanding in a team whose cohesion is growing.
"He (Rooney) is enjoying the position he's playing in at the moment because it has given him a lot of freedom to use his energy, in that position you do need energy," Ferguson told a news conference after Tuesday's victory.
Similarly effective has been the evergreen Ryan Giggs, who was involved in all three of his team's goals in the tie, a feat made all the more remarkable by the fact he is now 37.
"His experience and composure are vital," Ferguson said of the Welshman. "He's just a unique person and player.
"He's lucky, in the sense he's got a physique that doesn't carry any weight, he's got fantastic balance... he looks after himself. To play at 37 years of age there must be tremendous sacrifice to do that."
