Well done to Burnley, they deserved their victory last night. A spell of pressure which resulted in Robbie Blake's stunning volleyed goal, followed by a much longer period of United being unable to convert possession into goals led to one of the Premier League's greatest shocks.
The question is, where does it leave United now? Well, it's no crisis. United have had similar slips at the start of previous seasons and still won the league.
I wonder how many people thought last night "if only we had Ronaldo...". It's a notion that will raise its head any time the Reds drop points this season.
United are a different team without Ronaldo, that's undeniable. Now it's a matter of the players finding their feet in this new format, the new system and way of playing that Sir Alex said was necessary. That seemed evident at Turf Moor. Even Sir Alex himself is still toying with what works, what doesn't.
I think that's the crux of it; the team dynamics have totally changed. And playing Burnley, their first home game back in the top flight for 33 years, it was always a potential stumbling block.
United's defensive disruptions have come at the worst possible time, too. The Reds' rearguard was the solid foundation of last term's successes and, at a time of transition of sorts in attack, to suffer injuries to Rio Ferdinand, Nemanja Vidic and Edwin van der Sar so early on has been a damaging blow.
And Owen Hargreaves' return - whenever that may be - could be critical as, if Fletcher isn't playing at the moment, United's midfield doesn't seem to have the same energy.
But, first things first, the Reds need the right response on Saturday against Wigan. No panic, just get back on track. The team's promising constituent parts also have to gel - and expectations at United dictate that it must happen quickly.