Argentina's Sergio Aguero equalized early in the second period with a great shot from the corner of the box into the top corner of the goal defended by Czech Petr Cech.
With the score tied, both teams had chances to break the deadlock, but this was maintained until the 90th minute, with the 'gift' of Nastasic and Torres slip Hart.
"We won a game that was very important to us," said Mourinho. " Maybe we won the best team in the Premier League."
On Torres, Mourinho said that he had seen "the best Fernando, after missed a clear chance ".
With the victory, the fifth consecutive Chelsea in all competitions buy ultimate team coins, Mourinho's team placed second in the standings with 20 points, level with Liverpool and Arsenal two leader, who on Saturday won their visit to Crystal Palace for 2 -0.
The City, meanwhile, falls to the 7th position and is already six points behind, leaving a delicate position coach, Manuel Pellegrini.
"In the second half we had control of the ball, but what happened as it happened in other losses " estimated the Chilean, who said that next week " will discuss " Chelsea 's second goal, although he would not hold Zabaleta or Hart.
Spurs Win
In other games on Sunday, Tottenham defeated by the minimum Hull City (10th ) with a penalty goal Spanish striker Roberto Soldado. The Spurs are fourth, three points behind Arsenal.
Eel Swansea (9th) were held to a goalless draw at West Ham (15th) and Sunderland (19th) achieved the first victory of the season by winning at Newcastle (11th) 2-1 and off the bottom of the classification.
On Saturday, in addition to the victory of Arsenal, Liverpool beat West Brom 4-1, with three goals from Luis Suarez, to keep hunting for the Gunners.
Manchester United came from behind against Stoke City (17th ) to avoid a fourth defeat of the season and now is eighth with 14 points, two of the rival City.
