United put the champions-elect to the sword in style with our best performance of the season to reignite our hopes of a top four finish.
Goals from Marcus Rashford and Ander Herrera secured a thoroughly deserved win as we ended a winless 12-game run against the west London side.
Jose Mourinho rested Zlatan and Henrikh Mkhitaryan but got one over on his former side at the third time of asking - after two defeats to them so far this season - with a magnificent tactical masterclass.
This was United's best showing of the season by some distance with Antonio Conte's side harried into submission as the visitors failed to register a shot on target all afternoon.
The result cut Chelsea's lead at the top to four points following Spurs win over Bournemouth but, more importantly, lifted United back to fifth - four points behind City (with two games in hand).
Marcus Rashford set the tone for what was to follow in the fifth minute when he outpaced David Luiz and pulled his effort narrowly wide.
Two minutes later, the young striker got his side off to the perfect start with a brilliantly-taken finish.
Despite his handball in the build up, Ander Herrera - magnificent throughout - picked out Rashford with a pinpoint pass and he ran through to slot in beyond stand in stopper Asmir Begovic.
Begovic thwarted Jesse Lingard with a good low save, Ashley Young fizzed a shot wide and Gary Cahill's misdirected header almost flew into his own net.
It got better for the Reds four minutes after the restart after good work from captain for the day Young.
He drove into the box after his initial cross was cleared by Luiz before he cut the ball back for Herrera.
The Spaniard capped an immense individual performance with a deserved goal when his effort deflected off Zouma and wrongfooted Begovic to extend our lead.
Lingard went close from distance, Rashford fired into the side netting and then tested Begovic with a 20-yarder that the keeper did well to save.
Chances were at a premium at either end from then on with David de Gea, on his return to the team, largely untroubled.
Conte's side had only lost four league games all season but were unable to respond as the Reds saw out a first win against the Stamford Bridge since 2012.
Overall team performance: 9.5/10
United Faithful Man of the Match: Ander Herrera. Man marked Eden Hazard out of the game and typified the team's performance. Magnificent and simply immense.