Nemanja Vidic struck his first goal for the club in the triumph.
Mancini said: "I am satisfied with the result and the first half performance, but not the second. We lost intensity and that was to a degree expected with three forwards behind Icardi.
"We kept losing possession and that's a problem when all three are short on match fitness. Lukas Podolski has always played that role, while Hernanes is learning and Palacio fits right in. Guarin has the physique to play there. If he learns and improves, then he can do it."
This was Inter's first home victory since October, but Mancio warned against heralding a new dawn.
"We are working well, but a win won't change our path. It was important to get the result today with this very attack-minded formation. It's tough, but with the right fitness levels we can play like this regularly."