Roberto Mancini was left to rue his side's missed chances as they suffered a shock 1-0 defeat against Swansea at the Liberty Stadium.
Swansea's free flowing style forced Mancini into a first-half change which saw Sergio Aguero replace Gareth Barry as they tried to take the initiative.
Luke Moore was summoned from the bench and duly delivered a winning header after 83 minutes as City wasted chances to draw level.
"I think they played very well for the first 35 minutes, they were aggressive and had possession," Mancini told Sky Sports.
"In the last 10 minutes of the first half and in the second half, we had control of the game.
"We had some chances where we should have scored but didn't and we made a mistake for their goal."
On his first-half decision to withdraw Barry, he added: "They had a lot of possession so we needed another striker, so that we could press high and make it hard for them to play from the back.
"We had chances on the counter attack but we needed to score. It's like against Sporting, if we don't score they can always score. I don't think we deserved this result."