The West London club were beaten 2-0 by City at the Etihad yesterday just two weeks after the Blues surprisingly won at the same venue in the league to blow the title race wide open.
Chelsea are currently top of the Premier League, but City are still the favourites with the bookies which is something that clearly riles Mourinho.
The Portuguese boss admitted that City were the better side yesterday and that they are the main team to battle with in regard to the Premier League.
“City played much better than us and they deserved to win much more than us,” he said.
“When the best team wins I think football is at peace. Two weeks ago the best team won, and today the best team won. So that’s simple.
“It gives more credit to my players, because to win twice against City during the season, the game proved today that it is very, very difficult to do it.
“They were the best team today, they deserved to win and they did.”