The Reds exploded out of the blocks, sweeping a fragile looking Chelsea team aside and establishing an apparently winning 2-0 lead after only 11 minutes of play.
By halftime Chelsea looked finished and I think, at this point, most spectators were thinking that the only thing in doubt was United’s eventual margin of victory.
However, like so many other occasions this season, their dynamic opening evaporated as the game progressed as they sat deeper and deeper and allowed Chelsea to come onto them in waves.
The introduction of Eden Hazard and John Obi Mikel, in place of the ineffectual Victor Moses and strangely subdued Frank Lampard, after only seven minutes of the second half, was pivotal in Chelsea’s recovery.
This was despite the more ignorant element of the Blues supporters chanting “you don’t know what you’re doing” to the beleaguered interim manager Rafael Benitez who actually made what turned out to be a brave and inspired decision.
United were the architects of their own demise in this match and really must learn to put teams away when they are controlling things as they were in the first half.
Their dominance in this period was notably exemplified by Michael Carrick who seemed to be orchestrating everything, Tom Cleverley who continually buzzed in and around Chelsea’s static midfield and the majestic Rio Ferdinand who appeared in total command at the back.
The performance of Ferdinand, in particular, defied belief that the watching England manager, Roy Hodgson, can continue to ignore his claims for an England recall.
Indeed The Daily Mail, amongst others was demanding this morning that Rio gets his place back sooner rather than later.
It all augured well for a semifinal place.
Unfortunately, almost as soon as they took the lead, United’s game plan seemed to change.
They dropped deeper, leaving Javier Hernandez isolated up front and presumably decided that the best tactic was to draw Chelsea onto them and catch them on the break.
This failed, as it has on many occasions this season, and it eventually made for a very nervy final few minutes when only a miraculous save with his foot from David de Gea kept United in with a sniff of the twin towers.
Sir Alex Ferguson blamed tiredness from Tuesday’s exertions for his team falling away in the second half. However, Chelsea, who played away in Eastern Europe on Thursday, may have had a better excuse on that score.
Certainly Carrick, Cleverley, Patrice Evra and Rafael de Silva, amongst others, looked very weary towards the end and the full-backs, could certainly benefit from a rest next week.
United’s ball distribution in the second half was abysmal.
They were profligate in possession and they ended up chasing the game and the ball for long periods adding to the workload and the fatigue.
Sir Alex must also be concerned with the form of some of his key players.
Wayne Rooney, despite the rather fortuitous goal, looked well short of his best and frequently gave the ball away.
Antonio Valencia, who came on for the injured Nani, seems to have completely lost confidence in his ability and never looked like mastering Ashley Cole who was far from his best himself.
Even Robin Van Persie seems to have gone off the boil since his explosive first half of the season and has only scored one goal in United’s last 10 games.
Sir Alex has a mini crisis on his hands in what could turn out to be a crossroads in his season.
Controversially crashing out of the Champions League already and now facing possible elimination from the FA Cup, United could soon have just the Premier League title to chase from a season that promised so much.
Despite their seemingly unassailable 12 point lead in the league, a few points dropped in the next few weeks could, to use a well quoted Fergy phrase, trigger a “bum squeaky” finale to the season.
Success or failure at Stamford Bridge, whenever it may be scheduled for, could be paramount in regaining or further deflating United’s spirits.