The Spaniard scored in the 90th minute after a mix-up involving Joe Hart to earn the hosts a stunning late victory over their Premier League title rivals at Stamford Bridge
The match had been heading towards a draw after Sergio Aguero cancelled out Andre Schurrle’s opener but the 90th-minute strike for the Spain striker, who had earlier hit the crossbar, means the Blues move up to second in the table.Ashley Cole returned to displace Cesar Azpilicueta in Jose Mourinho's only change to the Chelsea XI that beat Schalke 3-0 in the Champions League in midweek.
VIEW FROM STAMFORD BRIDGE
By Wayne Veysey
What a terrific encounter this was, turbo-charged in both atmosphere and pace. Fernando Torres had arguably his best Chelsea performance to date, shading the brilliant Sergio Aguero in the battle of the marquee centre-forwards with an outstanding display and the crucial winning goal.
Manchester City did not deserve to lose, but, once again, the finger of blame is pointed at Joe Hart, whose calamitous decision to come racing out of his goal in added time provided his critics with the greatest ammunition yet. Costel Pantilimon should prepare himself for an extended run in goal.
The reshaped heart of the visitors’ defence was found wanting in the third minute as a corner was partially cleared and Oscar found Cahill, who blazed over when unmarked at the back post.
City proceeded to dominate possession in the first quarter of the match without fashioning a clear chance and they offered up another for the hosts in the 29th minute.
For a second time, their backline was virtually non-existent as Torres ghosted onto Ramires' pass, only to fire over with the goal at his mercy.
The striker atoned for his error three minutes later, though, with an electric burst of pace to beat Gael Clichy and cross for Schurrle to enjoy a simple finish.
A seemingly rejuvenated Torres subsequently tormented City's other full-back, Pablo Zabaleta - cutting in past the Argentina international and his countryman Demichelis to rattle Joe Hart's crossbar with a superb curling effort.
Petr Cech then beat away a rasping shot on the turn from Aguero in the 42nd minute as City pressed for a way back into the game.
But Cech could do nothing four minutes after the break when the in-form Aguero made light of an acute angle to drill Samir Nasri's through-ball into the top corner -it was the Argentine's sixth goal in four outings and 10th of the season.
Chelsea were suddenly reeling and Cech gratefully grasped Garcia's free header from David Silva's free-kick after Ramires had become the fourth player into referee Howard Webb's notebook for hauling down Nasri.
From similar situations at the other end, Torres and John Terry passed up opportunities from Frank Lampard deliveries and, by the time Cech's left boot had denied Silva in the 65th minute, the contest was wide open.
Aguero searched for another inspired intervention as he lobbed over the far corner following a lightning-quick break involving Silva and substitute Jesus Navas, but it was Torres - and the unfortunate Hart - who were to have the final say.
Pellegrini's team had appeared the most likely winners heading into the closing stages, but as they pressed, Chelsea substitute Willian launched a hopeful ball forward that caused a horrific moment for City defender Matija Nastasic and goalkeeper Joe Hart.
Nastasic headed back towards his own goal, only to see the on-rushing Hart miss the ball to leave Torres with a simple finish for the winner.