It has been 13 years since AC Milan last won the Coppa Italia, but Sinisa Mihajlovic's side are through to the 2016 final after a 5-0 semi-final second leg win over third-tier Alessandria sealed a 6-0 aggregate result.
Having won the first leg 1-0 courtesy of Mario Balotelli's penalty, the in-form Serie A side completed the job at San Siro as Jeremy Menez and Alessio Romagnoli scored two apiece, with Balotelli adding late gloss.
While there was no dispute about Menez's measured finish and tap-in, Romagnoli's opening close-range goal – his first for the club – raised suspicions of offside and the assistant referee did initially appear to indicate as much, before changing his mind.
Alessandria provided a spirited second-half showing, but still succumbed to another Romagnoli goal and Balotelli's cool finish, and will return to Lega Pro action sitting just three points off a play-off spot.
Milan have not won the Coppa Italia since 2003, but will seek to end that wait when they face either city rivals Inter or Juventus in the Rome final in May.
The result extended their unbeaten run in all competitions to 12 matches, with Mihajlovic's men having lost only once in 2016.