United had come into the game in reasonably good stead, having beaten Fenerbahce 4-0 on Thursday night, but they were beaten out the gate today.
Indeed, the tone was set within 30 seconds, when Pedro gave Chelsea the lead, and from that point on Chelsea never looked back.
And neither did United - Jose Mourinho's side never seriously threatened to come back and win the game.
United look a ramshackle, no sign of Mourinho's stamp
So, just what the hell is going on with Mourinho's United?
How can they be playing so badly after so much investment, and after recruiting Jose Mourinho, until recently regarded as the best manager in the world?
The worrying thing for United is that Mourinho if anything appears to have taken the team backwards from the Van Gaal era - after buying Paul Pogba and Zlatan Ibrahimovic.
At least we now know that Wayne Rooney is not the problem - he wasn't even the squad today, and he was worse than ever.
Man Utd players trying to park the bus for Mourinho. https://t.co/v1pjUY87is #CHEMUN https://t.co/Tek8XxpLN5 — Telegraph Football (@TeleFootball)