Milan are now unbeaten in seven games in all competitions after an inconsistent start to life under new coach Paulo Fonseca.

The seven-time European champions are hoping to win a first Italian Cup since 2003 and only their sixth in total.

"It was a very good performance, the first half was magnificent and also helped me to rest some players," Fonseca told Sport Mediaset.

"I have only positive things to say, as we took it very seriously, I am very satisfied with the attitude of the players."

Chukwueze put the hosts in front in the 12th minute, bundling the ball into the net after his initial attempt had come back off the post.

Milan doubled their advantage barely five minutes later, as Tijjani Reijnders slammed home a brilliant strike when a loose ball fell his way outside the box.

Sassuolo were powerless to stop the waves of Milan attacks and Fonseca's side made it three in the 21st minute.

Chukwueze swept a shot into the far corner after being teed up by Tammy Abraham to complete his first brace since scoring a double for Villarreal against Real Madrid in April 2023.

The procession continued just two minutes later, as Ruben Loftus-Cheek drove forward and played in Rafael Leao to drill the ball into the bottom corner.

Fonseca took the opportunity to give some key players a rest, including Leao and Loftus-Cheek, by making four changes at half-time.

Milan scored again in the 56th minute as Davide Calabria netted his first goal of the season.

Samuele Mulattieri grabbed a consolation for Sassuolo shortly afterwards, but Abraham scored his fourth goal since joining Milan on loan from Roma with an excellent back-heel finish.

Earlier, Bologna reached the last eight for a second straight season with a 4-0 thumping of Monza.

The two-time winners took control of the last-16 tie with two goals in the space of three first-half minutes through Tommaso Pobega and Riccardo Orsolini.

Monza, who are struggling in the relegation zone of Serie A this season, were hoping to reach the quarters for the first time in 54 years.

But Benjamin Dominguez put the game beyond their reach in the 63rd minute, with fellow Argentinian Santiago Castro providing his third assist of the match.

Dominguez returned the favour for Castro with 14 minutes left, as Bologna notched back-to-back wins after their 3-0 victory over bottom club Venezia in the league at the weekend.