Thirty-nine year-old Zlatan Ibrahimovic, returning from coronavirus break, scored twice within 3 minutes to give Milan a 2-1 win over Inter in a dramatic Derby della Madonnina.
AC Milan had not beaten Inter since January 2016.
Ibrahimovic had missed four games and not played for almost a month after contracting COVID-19, but he put Stefano Pioli’s men two goals up inside 16 minutes on Saturday.
Romelu Lukaku got Inter back in it before the break.
Despite second-half pressure, Antonio Conte’s side could not force an equaliser as their four-match derby winning streak was ended.
There was one more twist when Inter were awarded a penalty when Donnarumma was adjudged to have brought down Lukaku in the closing stages.
However, VAR ruled the striker had strayed offside before the incident as in-form Milan held on to celebrate a famous triumph.
The victory took AC Milan to the top of Serie A with 12 points in four matches. Inter are languishing in the sixth spot with 7 points.