Chelsea manager Jose Mourinho admits he has been surprised by Fernando Torres since he returned to Stamford Bridge as the striker continued his revival with the winner against Manchester City.
The 29-year-old, who scored twice in the midweek Champions League win against Schalke, took advantage of a defensive mix-up in injury time to give Chelsea a 2-1 win.
Mourinho said: "I have had a big surprise with Fernando from day one with the way he works. He has worked so much from the first day."
He added: "Sometimes I have put him on the bench, sometimes he has not been selected, sometimes I have left him at home - but every day he has been the same. He has worked very hard."
City looked on course for a point when Sergio Aguero equalised after Andre Schurrle put Chelsea ahead - but confusion between goalkeeper Joe Hart and defender Matija Nastasic allowed Torres to pounce for the winner.
Mourinho said: "It was a fantastic performance from Fernando because it was built after an easy miss and that makes it even more valuable.
"He could have been affected for the rest of the game but it looked like that was the moment he said 'I will be man of the match'.
"We have done nothing with Fernando. It would be easy for me to say that, but he deserves credit. We work with our methodology and we believe it improves players in terms of sharpness and speed.
"I don't know if Fernando was the same last year but what I know is since I arrived he has worked very hard every day."
City manager Manuel Pellegrini refused to shake hands with Mourinho at the final whistle, saying: "I didn't want to."
He walked straight off at the final whistle but Mourinho insisted he did not intend to antagonise City when he went to the crowd to celebrate at the final whistle.
Mourinho said: "I wanted to buy a season ticket for my son and they gave him a season ticket behind the opponents' dug-out. I went for him - I promised him I would go to him and at the next match you will see him there again.
"This is the drama of the last minute. The emotion of the game."