Franck Kessie opened the scoring from the penalty spot before Rafael Leao scored brilliantly over the goalkeeper just after half-time.
Lautaro Martinez hit a perfect hat-trick for his first league treble for the club while Romelu Lukaku netted his 12th of the season to keep in touch with Cristiano Ronaldo (14) in the golden boot race.
The 10-times reigning Scudetto winner’s have failed to replicate their form of the past decade in Andrea Pirlo’s first season in charge, remaining a point outside of the top four and 10 adrift of Milan at the top, although with a game in hand.
Verona took advantage of a slip up from Lazio to go eighth, but Simone Inzaghi’s side continue to be the disappointment of the season, languishing in ninth.
For a side that finished fourth last season and just five points off the title, their position of just inside the top half and 15 points away from the top is certainly a less than desirable one.
Fiorentina are another underperforming side with four points currently separating them from the relegation zone. La Viola failed to back up their 3-0 win at Juventus, drawing 0-0 with Bologna at home.