Edin Dzeko's revival, aided by Aleksandar Kolarov, comes just as Roma are hitting stride, helped by a simpler run of fixtures after a brutal start.
Higuain, who scored 32 goals in his first season for the Serie A champions, has struck only twice this term.
New Roma striker Patrik Schick has been ruled out for a fortnight with a thigh injury.
They look so good that people are comparing this Napoli to the team of Diego Maradona. In fact, it might even be better, as they focus on the title.
Atletico Madrid goalkeeper Jan Oblak has brushed aside speculation that he is being lined up to succeed Gianluigi Buffon at Juventus.