The win took Milan into second-place on the table, seven points behind Inter.
Tomori said at the final whistle: "Who knows? At this point, we just have to focus on ourselves. Obviously, tonight was an important match, and I'm happy we managed to win: a good performance against a very, very strong team.
"The derby is always a special match and always difficult.
"We're happy to have won: now we'll enjoy this evening and focus on finishing the season strong."
"In these kinds of matches, the coach doesn't have to say much: it's a derby, and we know how important it is for the club, for us, and for the fans.
"We knew that the way we approached the first half could put them under pressure, and we would have had chances to score, as we did.
"We could have scored again in the first half; we had other dangerous chances. In the end, we're very happy with the three points."