Already seing their Europa League dreams hanging by a thread after a defeat at home to Empoli last week, Milan couldn't do much better against 18th placed Crotone.
Marcello Trotta opened the scoring for the Calabrian hosts, whereas the Rossoneri needed a second half strike from Gabriel Paletta to spare further damage.
Earlier this season Milan had comeback against Crotone but this time it was a point apiece at the Stadio Ezio Scida.