Chelsea moved within a point of league leaders Manchester City after easily beating Manchester United at Stamford Bridge.
The clash marked Jose Mourinho’s first return to west London since he was sacked by Roman Abramovich for a second time back in December last year.
But it was an afternoon to forget for the Portuguese tactician as his expensively assembled squad slumped to defeat against his former employers.
Pedro opened the scoring for the Blues with only 30 seconds on the clock – the fastest Premier League goal this season – before Gary Cahill smashed home his side’s second with 20 minutes played.
And Chelsea piled more misery on their former manager when Eden Hazard and N’Golo Kante scored second half goals to lift the Blues into the top four.
The result marks a third consecutive league win for Antonio Conte’s Chelsea and re-establishes their status as potential title challengers.
Chelsea took the lead almost immediately from kick-off as Pedro profited from some hesitant United defending. Marcos Alonso’s hopeful long ball caused confusion between Chris Smalling and Daley Blind, which allowed Pedro to poke the ball past the outrushing David de Gea, before tapping into an empty net.
United responded well to falling behind as they looked to find an immediate equaliser. Antonio Valencia stood up a cross for Zlatan Ibrahimovic, but the Swede headed over Thibaut Courtois’ crossbar despite getting the better of Cesar Azpilicueta in the air.
But the visitor’s momentum was cut short when Cahill smashed home from a set-piece delivery midway through the first half. Ander Herrera failed to clear Eden Hazard’s corner, leaving Cahill the freedom of the penalty area to lash the ball into the back of the net.
Chelsea were in full flow as they tried to end the game as a contest. Blind was robbed by Pedro, whose low cross was kicked away by De Gea, which prevented Diego Costa adding what looked to be a certain third goal.
Herrera produced United’s biggest threat on goal in the first half when his long-range shot was palmed away by Courtois. The goalkeeper failed to hold onto the Spaniard’s effort, but was quick to react as he denied Jesse Lingard’s rebound.
The home side stretched their lead just past the hour mark when Hazard dribbled his way past Smalling before firing past De Gea. Nemanja Matic played a clever one-two with Hazard, to allow the Belgian onto his right foot, who curled the ball past a helpless De Gea.
Jose Mourinho was left humiliated with 20 minutes left to play when Kante added a fourth for a rampant Chelsea. The summer signing from Leicester City easily dribbled past Paul Pogba and Smalling, leaving Kante the chance to steer past a furious De Gea.
United nearly pulled a goal back through Ibrahimovic in the closing stages but a fine save from Courtois ensured the Belgian held onto his clean sheet. Ibrahimovic teed himself up nicely in the box, but his snapshot was well saved, leaving the striker without a goal in his last five league games.
The result leaves United in seventh place and six points off top spot, with Jose Mourinho’s winless in their last three league games.