Roberto Mancini believes Manchester City can still win the title though he conceded that if they had lost to Chelsea the gap with Manchester United may have been too big.

City are 12 points behind the leaders after their 2-0 win but, asked if 15 would have been too big a margin, the manager said: "Maybe, maybe – but I think football is finished when it's finished, the last minute of the last game. If we arrive with four games to go and United are 12 points ahead, it's finished. But I think that our job is to continue to work.

"For us now it's not important to look at the table, only to continue to work like today, play well and improve, only this, and then maybe look at the table in one month or 40 days.

"We can't think it is finished with 11 games to go. We can't think this and it's not my mentality. I don't want this in the players' mentality. We need to think like this game – only this. We can do better but in this game it was important we had a clean sheet, we had two goals and we had other chances against Chelsea. We did well."

Mancini was critical of Joe Hart and Kolo Touré over their roles in the penalty won by Demba Ba early in the second half when the striker eluded the defender before the keeper brought him down. "I say to him everything when he did a fault because I think we can't concede a penalty like this from a kick [pass] 45 metres out. Kolo and Joe both did a mistake. But after that we were fantastic," the manager said.

Hart, who saved the penalty from Frank Lampard, accepted blame for its award. "It was nice to save it but I'd given it away so I had to save it. I work a lot with Lamps and he is a great penalty-taker. He's a big hero of mine, if I'm honest. We spoke about it [before the spot-kick was taken] but I'm sure it's not mind games with Frank. He's not going to be put off by an idiot like me. So it was a case of trying to go to the right and getting a strong hand on it."

Of City's title challenge Yaya Touré said: "We have 11 games and it will be very tough for us but we will keep going, that is the most important thing, to try to continue to win. It was important. We know United are very strong away and at home. The first half was quite good but we missed a couple of chances and in the second half Joe made a big save. He made the difference. We tried to keep a clean sheet and then gave a lot to score. Big, big credit to the team."

Chelsea dropped seven points behind City, though Rafael Benítez claimed they could still finish second. "Winning would have moved us closer but I thought it would be a fight until the end of the season and it still has to be the same," the manager said. "We have to keep pushing and trying to win our games."