Kaka struck the winner ten minutes from time and Ancelotti said afterwards: "In other times we would have lost games like this.
"The team showed it has quality both in terms of technique and strength of character. I can comfortably say Atalanta played better than we did and they didn't deserve defeat.
"We struggled today because the team could not seem to move in its usual manner and was under pressure.
"In the first half we were too timid, especially when going in for loose balls. After the break we went out there with a more incisive attitude and took advantage when Atalanta ran out of steam."