The Blues ended the 2011/12 Premier League champions’ 100% home record this season with a shock victory at the Etihad Stadium courtesy of a Branislav Ivanovic strike.
The result leaves the Londoners just two points adrift of table-topping Arsenal, who now enter a difficult run of fixtures.
Although his side are undoubtedly in a strong position, ‘The Special One’ played down any ambitions of lifting the trophy at the end of the campaign.
“We are there, but we are not favourites,” Mourinho told Sky Sports.
“I just think it is very important because it is not good for the evolution of the team if you are playing in the Premier League 10, 15 points behind the leaders.
“It is not good for the evolution of the team if you are playing Europa League. We need big things… we need these kind of matches with the pressure we felt today and this for the team is very important.
“I think we played fantastic, against a fantastic team. To play the way we did, I think is amazing for the boys in this process of building the team and prepare the team to be one of the favourites next season.”
Chelsea sit level on points with City with the half way point of the season now gone, and moved six points clear of fourth-placed Liverpool.
Mourinho’s side also became the first team to prevent the Citizens from scoring at home since 2010.