Mazzarri's team are six points adrift of leaders Juventus, but after Friday night's result only two points clear of third-placed Milan.
"I am focused only on tomorrow's game with Chievo, then at the end of the season everyone can look at the final table," he said.
"It is only normal that a superpower like Milan is getting closer, but the fact we're still in front is a sign of what an extraordinary campaign Napoli have had. We'll fight to the end and hope to finish as high up the standings as possible.
"Every game is a Final from here on in, starting with Chievo. We must continue along our path, trying to win every match. Chievo are to be feared, even if recently they have had a negative period.
"They will no doubt sit back and try to hit us on the break, as they did against Juventus. It's also a sign that when Napoli attack, we scare other teams. They are very worrying when they go on the counter-attack."