The City boss was not too happy with the way that the side had played in the first half of the game at Eastlands but was satisfied with the second half performance when a Carlos Tevez hat-trick earned City a 3-0 win against Roberto Martinez's side, who had Gary Caldwell sent-off with the score still at 0-0.
"The result was the most important," Mancini said after the match.
"I think in the second half we played better than the first half.
"I didn't like the first half because for me we didn't play good football.
"But we changed the tempo, probably after the red card the game was changed."
Mancini also gave special praise to Tevez after the game: "He scored three important goals and we won the game.
"I am very happy for him."