Milan face Inter this weekend.
Antonini said: "It was important to win today because it gives us a morale boost for the game against Inter. We have all week to prepare for this challenge in the best way.
"We have always believed to be able to reach this position in the standings thanks to the strength of the group, the ability of the players, the spirit and form.
"The Sunday game against the Nerazzurri will be important because the derby could end either way, but we will try to bring home the victory."