Defeat at Sunderland for the third successive season, coupled with United's battling 4-3 home victory over Newcastle, saw Sir Alex Ferguson's men reach the halfway stage of the Premier League season with a commanding lead, but one the Italian is confident is far from decisive.
He said after the 1-0 loss: "It hasn't changed. At this moment, United are better than us, they are at the top, but we have time to recover.
"We need to resolve our problems before and after, maybe we can win. It's no problem, seven points.
"That's not important. We know United are a fantastic team and probably they will win every game, but the season is long and it is not important if it is six or seven or four points."
The most pressing problem Mancini has to resolve, in his view, is their propensity to be "too soft" in attacking positions.
They did pass up a series of opportunities at the Stadium of Light - skipper Vincent Kompany hit the bar with an early header and Yaya Toure, David Silva and Sergio Aguero were all denied by the excellent Simon Mignolet.
Ultimately, it was City old boy Adam Johnson, who left the Etihad for Wearside in a £10million summer switch, who proved the difference between the sides when his 53rd-minute shot squirmed underneath the flat-footed Joe Hart.
Mancini was furious that Johnson had the chance to win the game after Pablo Zabaleta appeared to be caught by Craig Gardner during the build-up, but referee Kevin Friend waved play on.
The City manager said: "How the referee can't see that foul, I don't know.
"The referee ate too much for Christmas. He was not in good form. He and the linesman, I think, after Christmas, it can happen to have a bad performance like today."
However, Mancini refused to criticise Hart for his part in the goal despite the keeper appearing to have moved too far to his right to get back across in time to repel Johnson's effort.
He said: "Johnson was really clever because Joe thought that Johnson was going to cross and instead, he shot.
"He did very well, Johnson."