AC Milan moved three points clear at the top of the Italian Serie A with a dominating 4-0 win at Palermo while Juventus were held to a 1-1 draw at home by Chievo.
Zlatan Ibrahimovic, who was suspended for three games, made an emphatic return Saturday as he scored a 14-minute hat-trick while central defender Thiago Silva added a fourth goal.
Milan head coach Massimiliano Allegri reckoned it as "a crucial victory, which allowed him to focus on his side's Champions League campaign".
"We put in a great performance today and the lads did so well right from the start. Ibrahimovic scored three wonderful goals," he was quoted as saying by Xinhua.
"Winning in Palermo was important and I believe this can be a crucial victory. Robinho did very well, creating assists and working for the team," he added.
Juventus stumbled in response to AC Milan's win by being held to a 1-1 draw by Chievo.
Paolo De Ceglie put the Bianconeri in front in the 18th minute, but they failed to build on their lead and were punished when Boukary Drame levelled for Chievo in the 76th minute.
The draw leaves Juve three points behind Milan with a game in hand, one which must now be won if Antonio Conte's side want to return to the Serie A summit next Wednesday.
Juventus manager Conte thought Juventus deserved to win, and warned fans they are "performing miracles" to be in the title race at all.
"The team has to grow, because there are much more organised sides than us right now. In the summer there was talk of this squad being good enough only for sixth place, so what we're doing now is performing miracles," he said.