Chelsea maintained a seven-point advantage over Tottenham at the top of the Premier League with a hard-fought 2-1 victory over Manchester City.
Pep Guardiola suffered league defeats home and away to the same opponents in a single league season for the first time in his managerial career as City are now left to fight for a top-four place.
Eden Hazard gave Chelsea a 10th minute lead when his shot deflected off returning City captain Vincent Kompany past keeper Willy Caballero, who should have done better.
Chelsea keeper Thibaut Courtois was also badly at fault when his poor clearance to David Silva set up Sergio Aguero’s equaliser after 26 minutes – but Chelsea were back in front before half-time.
They were awarded a penalty after Fernandinho tripped Pedro and even though Cabellero saved Hazard’s spot-kick, the rebound fell kindly for the Belgian to score.
City, who stay in fourth, had the better chances in a tense second period, with Kompany’s header bouncing back off the bar and John Stones shooting over from six yards in injury time. Chelsea, however, held on for a win that was even more vital given Tottenham’s dramatic late comeback at Swansea City.
Chelsea’s progress towards the Premier League title has been a tale of almost unbroken serenity since manager Antonio Conte reworked his tactical approach after successive losses at home to Liverpool and away to Arsenal in September.
This was arguably their biggest game since as it followed on from the shock home loss to Crystal Palace and it was against a Manchester City side with the talent and capability to make this night at Stamford Bridge a real test of nerve.
And so it proved as City, with David Silva the orchestrator supreme, putting Chelsea’s defence and their supporters on edge right until the final whistle.
Chelsea emerged triumphant thanks to the mixture of talent and resilience that has served them so well this season and the celebrations at the final whistle reflected just what a significant night this might prove to be.
Eden Hazard provided the flourishes but manager Conte proved his pragmatism with the introduction of Nemanja Matic for Kurt Zouma at the start of the second half to attempt to lock down Silva and the win.
It worked to an extent but Chelsea also enjoyed good fortune as Kompany’s header bounced back off the bar and Stones somehow scooped an injury-time chance over the top.
In the final reckoning, Chelsea showed the bloody-minded defiance of champions – and this is the sort of result that could earn them that crown.
If this meeting of two of the Premier League’s superpowers and two elite coaches was meant to be an enjoyable experience, you would not have known from the body language of Chelsea coach Conte and his Manchester City counterpart Guardiola.
Guardiola, in particular, appears to lead an agonised existence in his technical area. The advocate of the joyous, beautiful game looks as if he is going through torture in almost every game.
He was slapping his thigh and remonstrating with backroom staff within 15 seconds of the kick-off and he was in regular dialogue with fourth official Bobby Madley, with Conte occasionally joining in.
It was, it should be stressed, another frustrating night for Guardiola when his team promised much and ended with nothing – although it concluded with a warm handshake for Conte, who also looked like he had endured a tough night.
Conte, by his standards, was relatively low-key but the mask dropped at the final whistle as he pumped his fists in the direction of Chelsea’s fans. This was a huge night for the Italian as he did the double over Guardiola.
Manchester City remain the great enigma of the Premier League – looking like they could score every time they attack but liable to concede at any moment.
Guardiola still has a goalkeeper conundrum, with Willy Caballero unconvincing and caught out by a routine deflection from Kompany for Hazard’s first goal, while there is an air of permanent frailty at the back.
City’s slim title hopes are now over and they must hunt a top four place, aided by Bournemouth’s late equaliser at Liverpool, and the FA Cup.
They must achieve one of both of those target to stop this season ending unfulfilled before Guardiola tackles those goalkeeping and defensive problems in the summer.
Arsenal 3-0 West Ham
Hull 4-2 M’Boro
S’thampton 3-1 C’Palace
Swansea 1-3 Tottenham
Chelsea 2-1 Man City
Liverpool 2-2 Bour’mouth