David Neres continued his impressive performance by slotting home Napoli's fourth goal just 12 minutes later. Shortly after, Scott McTominay sealed the victory by scoring his first goal for Napoli, seconds after coming on as a substitute for Giacomo Raspadori.
What should have been a complication-free evening for Napoli, who rotated ahead of Sunday's Serie A clash with Monza, was made more difficult when rival fans began throwing flares and firecrackers at each other during half-time.
The second half was delayed by seven minutes following the latest incident between supporters as trouble has marked this week's cup ties.
On Wednesday, there were widespread clashes between Genoa and Sampdoria's hardcore ultras before and after their local derby, won on penalties by Samp.
Italian media report that both Genoa and Samp may have to play their next two home matches behind closed doors after dozens of injuries on a night of tension in the Italian port city.
Listen to the latest songs, only on JioSaavn.com
Napoli fans were also involved in clashes with Cagliari fans in Sardinia earlier this month.
Advertisement
(Except for the headline, this story has not been edited by staff and is published from a syndicated feed.)