Dries Mertens converted two penalties in his hat-trick as Napoli hammered promoted Benevento 6-0 on Sunday to go top in the Serie A on goal difference.
Juve won 3-1 at Sassuolo, with league top-scorer Paulo Dybala also grabbing three goals.
Napoli and Juventus have a maximum 12 points each, and so do Inter Milan who won 2-0 at Crotone Saturday.
Napoli settled matters early in their regional derby with guests Benevento, with Allan, Lorenzo Insigne, Mertens and Jose Callejon on target before the interval.
Mertens then struck twice from the spot for a five-goal tally alongside Inter's Mauro Icardi.
