Zlatan Ibrahimovic scored the only goal of the game, which allowed Milan to move six points clear of Inter in the standings.
"I saw the game with my son Luigi and we enjoyed it together after the disappointments of the last three derbies," Berlusconi said.
"It's true, it was an important victory, very important, that confirms the value of our team, which is built to win the Scudetto and the Champions League.
"We are top of the table and this makes us hopeful also because of the way in which we won, because ours was the victory that everyone desired, not just Ibrahimovic who made the difference with the penalty.
"It's a victory, which is the fruit of great sacrifice, obtained with clenched teeth because we played almost the entire second half with a man less.
"Don't forget that we were missing Pato, Inzaghi and Ronaldinho.
"We are happy to have focused on Allegri who has wide freedom of choice, like all Milan Coaches."