AC Milan's unbeaten Serie A start collapsed

AC Milan's unbeaten Serie A start collapsed as Samuel Mbangula's hat-trick inspired Bologna to a 4-2 victory at San Siro, only their second win in 22 league meetings.

The hosts had made home a fortress, but Bologna struck first when Mbangula swept home Nadir Zortea's cutback on his maiden Serie A start.

Milan hit back instantly. Arthur Theate's error allowed Alphadjo Cisse to equalize, then Fikayo Tomori teed up Cisse again on 27 minutes for 2-1.

Bologna roared after the break. Juan Miranda's cross forced Davide Bartesaghi's own goal to level, before Miranda set up Mbangula for 3-2.

Milan managed no second-half shot until Francesco Camarda headed wide late, and Mbangula sealed his treble on the counter, handing Raffaele Palladino a third straight away win.