Ibrahimovic praised Milan's work rate, insisted Inter are not out of the title race and apologised to Marco Materazzi.
"This great victory came from an excellent performance, especially in the second half when we were a man down. The team played with hard work, heart and sacrifice," he said of the 1-0 Derby della Madonnina victory.
Ibra earned and converted the decisive penalty after just five minutes, while the Rossoneri had Ignazio Abate sent off on the hour mark.
"We said that we are a team and play the way we know how. We created many chances in the first 20 minutes and could've got another two goals."
The Swede was also involved in an accidental clash with Materazzi, which saw the Inter defender stretchered off after a knock to the head.
"I didn't do it on purpose. I tried to get the ball, but he was there too and we both went for it. I apologised and these things can happen in football."