Juventus substitute Simone Zaza believes he struck lucky when deciding the most anticipated game of the Serie A season.
His 88th-minute goal, which took a telling deflection off Raul Albiol, means Juve boast a one-point advantage after dislodging the Azzurri from first place.
Zaza believes the title is now Juve's to lose and hopes his teammates can protect their new status.
Following Saturday night's match he told juventus.com: "I really hope my goal proves crucial when it comes to deciding the destination of the title.
"I was lucky, though," Zaza said. "It was down to the hard work of my teammates, we all played well in a difficult match.
"It was tough, we had to deal with all of their counter-attacks, but our goal throughout was to win, and we did it ... so that's OK.
"Now it all depends on what we do. If we can keep playing that way then no one will take the title away from us. We are now the top dogs.''
Defeated visiting coach Maurizio Sarri was crestfallen after watching Juve snatch all three points at the death.
Napoli had led the division since deposing Inter Milan over the festive period, but must now hope Juve slip up at some point across the final 13 games.
At his post-match news conference he said: "I'm disappointed we conceded right at the very end. We spent the whole game defending really well.
"We have to stay calm, because we can't let a deflected finish dash our self-belief. We played really well and it's rare to see Juventus create so few chances at home. We, however, should have done more up front.
"There are not many teams in Europe who can come to this stadium and match Juventus. We did that.
"We must react immediately. To become a great team you have to learn from bad experiences and move on from them very quickly.''