"I did not expect so many goals, but I did predict an entertaining encounter," said Leonardo.
"Cagliari were unbeaten in four and had kept three consecutive clean sheets. I knew we'd have to be very careful, but at the end of the day we did create many scoring opportunities.
"We are an attack-minded side and that causes a lot of problems for our opponents."
He added: "Our position has not changed. Milan must always think of achieving something important. Now we need to be sharp, logical and evaluate our potential with each round. It's difficult to say what we can do this season, but victory is in our DNA."