Chelsea made it eight Premier League wins in succession with a truly magnificent victory at Manchester City.
That winning streak looked under threat when Gary Cahill inadvertently sliced a Jesus Navas cross into his own goal to give the hosts a half-time advantage.
But a frankly stunning comeback instigated by a Diego Costa equaliser handed Chelsea all three points.
Having made it 1-1 with a brutish finish, he then set up Willian who slotted past Claudio Bravo with ease.
City pushed for a leveller but were caught out in the 90th minute as Hazard raced through to slot home.
And there was still time at the end for City to further disgrace themselves as first Sergio Aguero was dismissed for a horror challenge on David Luiz. Fernandinho followed after pushing Cesc Fabregas into the crowd as City finished with nine men.
It was a shameful end to the match as City lost all their composure.
Comprehensively beaten and totally out-thought tactically by Antonio Conte, Pep Guardiola now has a four-point deficit to make up as the Blues consolidate top spot.
Not since April 2009 had City lost a home game having taken the lead – and this match was decided by one guilt-edged miss by Kevin de Bruyne.
The former Chelsea man inexplicably hit the bar early in the second half from just two yards out with the score at 1-0. Minutes later, Costa had equalised.
A raking ball from Fabregas found the Spaniard, who shrugged off Nicolas Otamendi with ease. He took a touch before rifling home past the goalkeeper for his 11th of the season.
Costa then turned architect himself as his superb threaded pass allowed Willian to steal in and steer the ball home on 70 minutes.
And the win was well and truly sealed when Hazard raced in behind the City defence to tuck Alonso’s through-ball into the bottom corner.
Bravo then had to make a terrific low save from Willian to keep the score down as the Blues threatened to run riot. However, late nastiness from City threatened to mar a magnificent showing.
Having over-run the ball, Aguero committed a disgraceful, knee-height lunge on Luiz and was rightfully sent off. In the aftermath, Fernandinho pushed Fabregas into the crowd right in front of the Chelsea dug-out and was duly dismissed.
Fabregas showed great maturity not to retaliate as Fernandinho continued to push him, emphasising the gulf in class – both on and off the pitch – between the two sides.
City will complain that a decision not to earlier at least book Luiz for a block on Aguero did not go their way – but the Chelsea juggernaut simply rolls on.