"Top, cream of the crop, he's fantastic", United manager Jose Mourinho said after his side's win over Chelsea two weeks ago.
Willian opened the scoring in the 25th minute before a Martin Kelly own goal doubled Chelsea's advantage seven minutes later.
Here, Chelsea trampled all over their London rivals throughout the first-half and by the break the game was over, allowing Antonio Conte to start resting his stars as he turned his attention to Wednesday's (March 14) crucial trip to Barcelona.
Seven minutes later and the home side had doubled their lead with a goal equal parts attractive and gormless.
The first chance of the second half fell to Alexander Sorloth who struck the post from close range with two minutes played.
A deflection off Kelly was also responsible for the first goal so, if you wanted to be harsh, you could credit the defender with two own goals.
Cesc Fabregas began it with an inch-perfect pass out to Marcos Alonso on the left.
He said: "Normally when you come against a team not having the best of times, that can be a very unsafe time to play them". A game that should have ended up as a simple practice for Barcelona, however, ended with Chelsea rattled by a late Patrick van Aanholt goal.
The defender played a part in both first half goals which put the Premier League champions in total command as they went on to record their first league victory since February 12.
Chelsea almost took advantage of that let-off, but Tomkins threw himself in the way of yet another goal-bound shot, this time from Willian, and Hennessey saved from Hazard.
Jason Cundy has warned Chelsea that they will need to defend better against Barcelona than they managed in a 2-1 win over Crystal Palace on Saturday evening. But Palace made and missed an even clearer opening when Christian Benteke moved into space at the far post as a corner came over from the left. The 22-year-old striker looked to beat Courtois at his near post but saw his powerful effort cannon off the post.
Replaced Giroud in the 72nd minute and did not have much of a contribution.
"It's all about timing for Palace".
Unused subs Caballero, Ampadu, Emerson, Moses.