Chelsea stretched their lead at the top of the Premier League table to 11 points after victory over battling Swansea City at Stamford Bridge.
Cesc Fabregas marked his 300th Premier League appearance by firing the Blues ahead, poking the ball through the legs of Jack Cork and into the net.
The hosts were stunned when Swansea equalised from their first serious attempt on target on the stroke of half-time – Fernando Llorente heading in Gylfi Sigurdsson’s free-kick.
Fabregas hit the bar before Pedro’s curling effort restored the lead and Diego Costa netted the third from close range.
Swansea were denied a penalty when Cesar Azpilicueta handled inside the area at 1-1.
This was far from straightforward for Antonio Conte’s side and had referee Neil Swarbrick awarded Swansea a penalty shortly before Pedro made it 2-1 then the outcome might have been different.
However, in the end Chelsea’s sweeping forward play earned them a 10th straight home Premier League win as they took another significant step towards a second title in three seasons.
On a weekend when the first major silverware of the season – the EFL Cup – is handed out at Wembley, the Blues look unstoppable. They have 63 points from 26 games – three more than at the same stage in 2014-15 when last crowned champions of England.