The Nerazzurri won despite Yuto Nagatomo's dismissal.
"I saw two great things, which were the approach Inter took to the derby, especially right at the start. I had not seen such aggression and determination from my men often," he said of the 1-0 victory.
"In a difficult situation with half the match a man down, we did not allow Milan to perform their greatest strength, which is close passing in and around the box. We forced them wide and never stopped trying to hit them on the break.
"I saw the character of an important team tonight, as it really was difficult to get the win."