كتب : وكالات
Jorge Martinez gave the visitors a shocking lead in the 25th minute before Kaka saved a point for the European champions midway through the second period.
Milan failed to win a league game since their victory in the Serie A opener.
They are located 11th with just seven points, trailing leaders and city-rivals Inter with as many points.
Milan travel to Scotland as they play Celtic in the Champions League later this week.
In Turin, a late strike from France forward David Trezeguet handed Juventus a 1-0 win over city rivals Torino.
Juve jump to second place on 13 points, one point adrift of Serie A leaders and holders Inter Milan.