AC Milan suffered their joint-heaviest ever Serie A defeat as they were hammered 5-0 at Atalanta in the Lombardy derby.
It equals the Rossoneri's worst-ever loss in the competition and is the first time since a 5-0 drubbing at Roma in 1998 that they have lost by a five-goal margin.
Alejandro Gomez opened the scoring after 10 minutes but Milan's collapse really began after half-time.
Atalanta struck twice in as many minutes just after the hour mark as Mario Pasalic and Josip Ilicic found the net.
Ilicic scored again after 72 minutes before Luis Muriel completed the rout seven minutes from time.
The humiliating loss leaves Milan 10th in Serie A and brings a four-game unbeaten run to a shuddering end.
Stefano Pioli replaced Marco Giampaolo in October and the 53-year-old has won three of his 10 matches in charge of the club.