A 5-1 thrashing of Frosinone helped Napoli reach the Serie A summit at the season's halfway stage after Inter suffered a last-gasp defeat to Sassuolo.
Being crowned 'winter champions' may hold significance for the San Paolo side, who were also top of the pile at the same stage when they last won the Scudetto in 1990.
Andrea Consigli's heroic performance in goal for Sassuolo and a last-gasp Domenico Berardi penalty at San Siro put Roberto Mancini's Inter under threat in top spot, and Napoli capitalised in ruthless fashion.
Maurizio Sarri's men dominated from the start at the Stadio Comunale Matusa and deservedly went a goal up after 20 minutes, as Raul Albiol found the net from close range following Jorginho's corner.
Manolo Gabbiadini replaced Higuain and got in on the act himself with the visitors' fifth and Paolo Sammarco netted a consolation goal late on.
