Manchester City 1 Chelsea 3: Blues complete brilliant turnaround in Etihad thriller
Diego Costa, Willian and Eden Hazard were on target as Chelsea laid down a marker in the Premier League title race by producing a superb second-half comeback to win 3-1 at Manchester City, who ended the match with nine men.
Leaders Chelsea travelled to the Etihad Stadium having won seven consecutive matches, during which time they had conceded just one goal.
Antonio Conte's men were staring down the barrel of a first defeat since September, though, when Gary Cahill diverted Jesus Navas' cross into his own goal on the stroke of half-time.
But a thrilling encounter turned when Kevin De Bruyne smashed the crossbar with the goal unguarded, with Costa levelling soon after.
Cesc Fabregas, starting a league match for just the second time this season in the absence of the injured Nemanja Matic, evoked memories of Chelsea's title-winning 2014-15 season when he played a stunning long ball from which Costa scored his 11th league goal of the campaign to restore parity.
Chelsea then completed the turnaround with 20 minutes remaining thanks to Willian's cool finish from a brilliant Blues counter-attack.
Eden Hazard then added late gloss to the scoreline for Chelsea, before the contest ended in ugly circumstances as Sergio Aguero saw red for a dreadful lunge on David Luiz, with Fernandinho also dismissed for his role in the resulting melee.
In a high-octane opening David Silva saw a penalty claim for handball against a sliding Cahill waved away, while at the other end Eden Hazard bent a shot just past the right post from 20 yards after good work from Pedro.
City had the ball in the net when Fernandinho headed home David Silva's free-kick, only to be rightly flagged for offside.
The hosts began to gain a foothold and David Silva's sumptuous ball was knocked across goal by Leroy Sane to Aguero, whose shot was brilliantly blocked by Cahill.
But Cahill had his head in the turf in disappointment on the stroke of half-time when he stretched to clear Jesus Navas' cross and succeeded only in flicking the ball into the top-left corner.
Chelsea almost shot themselves in the foot again after the restart, Aguero stealing in between Courtois and Cahill to intercept Marcos Alonso's sloppy backpass, only to see his shot was blocked on the line by Cahill.
It should have been 2-0 shortly before the hour. Silva set Aguero free on the right flank and his pin-point low cross picked out De Bruyne, who somehow hit the woodwork from point-blank range with the goal gaping.
And that proved costly just before the hour. Fabregas pinged a brilliant long ball towards Costa, who shrugged off Nicolas Otamendi and drilled his shot under Claudio Bravo.
City sought to quickly regain the lead and Aguero forced a smart stop from Courtois, but the travelling supporters were celebrating again in the 70th minute.
A lightning counter involving Fabregas and Hazard ended with Costa finding Willian, who calmly slotted into the bottom left-hand corner and paid tribute to the victims of the Chapecoense plane crash by holding up his black armband that read "Forca Chape".
City brought on Yaya Toure and Kelechi Iheanacho in a bid to find an equaliser, and Navas saw another penalty appeal for handball against David Luiz dismissed.
Chelsea's mood was dampened slightly when Costa was replaced in the closing stages after sustaining a knock, but they rounded off the win in the 90th minute as Alonso's brilliant lofted pass found Hazard, who clinically drilled past Bravo.
The match ended on a sour note when Aguero was rightfully sent off for an ugly two-footed challenge on David Luiz, similar to an offence he committed on the Brazilian in the 2013 FA Cup semi-final.
That led to a fracas between the two teams and Fernandinho was also given his marching orders for grabbing Fabregas - who appeared to have slapped the City midfielder - by the neck and pushing the Spaniard over the advertising hoardings.