The reigning Premier League champions squandered a one-goal lead to eventually lose 3-1 at Tottenham today, basically handing United the title as they sit 13 points with five matches remaining.
Despite the fact United are about to clinch the title, Mancini does not believe Sir Alex Ferguson's men are better, but did say they deserved to win this season.
"It (the title race) was finished three or four weeks ago," Mancini said.
"They are not a better team but they deserve to win this title because we lost a lot of points in games we probably didn't deserve to lose.
"But United won a lot of games in a row with goals and deserve to win the title."