(CNN)AC Milan suffered its heaviest defeat in 21 years after losing 5-0 to Atalanta, marking a new low for a club that was once the dominant force in European football.
The loss, which saw Atalanta score four goals in the space of 22 second-half minutes, sees Milan slip to 10th in Serie A with its eighth league defeat of the season.
Alejandro Gomez opened the scoring for the home side, before Mario Pasalic, Luis Muriel and a brace from Josip Ilicic completed the rout in Bergamo.
The result is a crushing blow for Milan, a team which once boasted a star-studded lineup that won five league titles in the 1990s and two Champions Leagues in the 2000s.
Milan had won two and drawn two of its four previous games ahead of facing Atalanta, but was made to suffer during a poor second-half showing that saw Muriel bag his 11th goal of the season and Ilicic his sixth and seventh.
"We got our whole interpretation of the match wrong," manager Stefano Pioli told AC Milan TV.
"We faced it in the wrong way and it became difficult to change our attitude and the match. On a tactical level, a technical level, and a physical level Atalanta were better than us.
"This is a defeat which really hurts."