Gonzalo Higuain scored twice as Napoli easily beat Frosinone to move top of the Serie A table at the halfway stage of the season.
Raul Albiol, Marek Hamsik and Manolo Gabbiadini also scored to take Napoli two points clear after 19 games.
Higuain's goals took his tally for the season to 20 in all competitions.
Napoli, who have not won the title since 1989-90, went top after previous leaders Inter Milan lost 1-0 at home to Sassuolo earlier in the day.
Albiol's close-range goal following a corner gave Napoli the lead in the 20th minute and Argentina international Higuain doubled the lead 10 minutes later with a penalty.
Hamsik, Higuain and substitute Gabbiadini all scored superb individual goals after half-time before Paolo Sammarco pulled one back nine minutes from time.
Higuain scored and converted the penalty that made it 2-0