Despite seeing his side lose to their cross-city rivals and slip six points behind them in the league, the Italian insists they are not out of the title picture just yet
The former Inter boss saw his side fall to a last-minute Robin van Persie free kick which completed a dismal week for the Etihad faithful as they also crashed out of Europe, finishing bottom of their Champions League group.
Nevertheless, the defeat, City’s first at home in the Premier League in two years, is a mere setback in Mancini’s eyes, and he believes there is still plenty to play for this season.
"Things aren’t going well but I know we will still have a great year," he told reporters.
"United have more experience but we have a much better team and play much better football. Six points is not a big difference with 24 games still to play.
"We need to try to win five or six games in a row to try and reduce the gap."
Mancini was happy with City's performance against United on Sunday and urged his players to keep on fighting for the title after winning the league title in the dying embers of last season against QPR.
"Even though we lost on Sunday, we showed that we are a really strong team and can win the title again," he added.
"We were unlucky. We dominated long spells of that game — and did not deserve to lose.
"The Premier League is the best league in the world at the moment and as we know from winning last year, you can lose a game in the last second."