Scotland midfielder Scott McTominay scored after 25 seconds for Napoli to claim his first Serie A goal and help them beat Como 3-1 to extend their lead at the top of the table.
The 27-year-old joined the Italian club from Manchester United at the end of August and had scored his first goal for them in their Coppa Italia victory over Palermo last month.
McTominay scored in Friday’s match when he fired home from inside the box.
Como equalised through Gabriel Strefezza’s low, long-range strike that sailed through a crowded box into the bottom left corner two minutes before the break.
Romelu Lukaku restored the hosts’ lead from the penalty spot eight minutes into the second half after Sergi Roberto brought down Mathias Olivera.
David Neres scored Napoli’s third in the 86th minute when he latched on to a through ball and converted a one-on-one chance to leave Antonio Conte’s side four points clear of Juventus, who host Cagliari on Sunday.
“I don’t know if this is currently a Napoli that deserves to be in first place in the standings, but we are first and that is a fact,” said Conte.
“If someone had told me this three months ago, it would have been difficult to believe.
“We’re growing in terms of temperament, and in our ability to adapt – playing good football, but also willing to get our hands dirty when we need to. That’s a great sign, and we have to embrace it fully.”