Jose Mourinho was humiliated on his return to Chelsea as his Manchester United defense was brutally exposed in a 4-0 loss Sunday by its ruthless hosts, who scored after only 30 seconds.
The Chelsea boss endured chants of "You're not special anymore" from home fans who adored the self-styled "Special One" when he was delivering titles across two spells in charge of the London club.
With Gary Cahill, Eden Hazard and N'Golo Kante also scoring after Pedro Rodriguez's lightning opener, this capitulation by United was reminiscent of the gloomy final days of Mourinho's second Chelsea reign which was abruptly halted last December with his firing.
United is quickly discovering the managerial aura which saw Mourinho win trophies with FC Porto, Chelsea, Real Madrid and Inter Milan will take a long way to being restored.
Counterpart Antonio Conte also had much to prove against Mourinho after losses to Liverpool and Chelsea in the opening weeks of his Chelsea reign. The Italian's players delivered before the first minute of the game had elapsed, setting the tone for a day of dominance.
The opener originated from a speculative long ball from Marcus Alonso which drifted past dithering defenders Daley Blind and Chris Smalling and landed at Pedro's feet. United goalkeeper David de Gea was already committed far from his goal-line at the edge of the penalty area and Pedro nipped around him and made no mistake putting the ball in the open net.
How United would then rue the miss by Zlatan Ibrahimovic who missed the target with a header. There was no way back for the record 20-time English champions, who have become a faded force since Alex Ferguson's retirement three years ago with David Moyes and then Louis van Gaal in charge.
It was another mistake by Smalling that allowed Chelsea to extend its lead in the 21st minute.
A Chelsea corner was flicked on at the near post by United's Antonio Valencia, then hit teammate Ander Herrera before the lethargic Smalling allowed Cahill to evade him and the Chelsea defender netted via Blind's back.
The game was becoming a reflection of the managers on the touchline. While Mourinho was subdued with his hands in his pocket, the energetic Conte was gesticulating enthusiastically.
And Conte was celebrating again just after the hour.
Eden Hazard started the incisive move that ended with a third goal. N'Golo Kante then squared to Nemanja Matic, who returned the ball for Hazard to turn Smalling before dispatching the ball into the corner of the net.
There was worse to come for Mourinho. Pedro, who started the rout, set up Kante to complete it. Kante waltzed through United's brittle defense with ease, going past Smalling — who else? — before slotting beyond De Gea.