Zlatan Ibrahimovic scored twice on his first start in two months as AC Milan beat Cagliari 2-0 on Monday to pull ahead of city rivals Inter on top of the Serie A table.
Ibrahimovic, 39, got the first from the penalty spot after seven minutes, adding a second just after the break in Sardinia.
Milan, targeting their first league title since 2011 when Ibrahimovic last played in the team, pull three points ahead of Inter who beat champions Juventus 2-0 in the San Siro on Sunday.
"This victory is a sign above all to ourselves more than Inter," said coach Stefano Pioli.
"We all want to bring Milan back to the top. The team will do everything from here to the end.
"Now we have an important game against Atalanta (Saturday), we focus on that, then in March and April we will see where we are."
Ibrahimovic proved he has returned to his best after injury, with the club set to sign former Juventus and Bayern Munich forward Mario Mandzukic to help their title push.
"Ibra will take care of keeping him (Mandzukic) at bay," joked Pioli.
The Swede brought his tally to 12 goals in eight games with five doubles, including a brace on November 22 against Napoli, when he picked up the thigh injury which sidelined him.
Milan shook of the absences of defender Theo Hernandez and midfielder Hakan Calhanoglu who tested positive for coronavirus.
The visitors quickly took control of the game after Cagliari defender Charalampos Lykogiannis fouled Ibrahimovic.
Ibrahimovic decided to take the penalty ahead of regular spot kicker Franck Kessie after the Swede had missed twice from the spot twice before his injury.
Cagliari goalkeeper Alessio Cragno cleared a long-range Davide Calabria effort after 24 minutes with the Italy defender hitting the post 10 minutes later.