Both sides meet in Natal next Tuesday knowing that defeat would spell the end of their tournament.
With both nations on three points, Italy need only a draw to join Costa Rica as Group D's representatives in the last 16 due to superior goal difference, prompting Cavani to claim that a "special performance" is needed to pip the Azzurri into the second round.
He told Il Mattino: "Now a huge game awaits us, certainly a difficult one against Italy. We must prepare it as best we can and put in a special performance.
"It is going to be like a final. Our fans have been fantastic so far in the tournament. They remind me of Napoli supporters."
Tuesday's encounter at the Arena das Dunas kicks off at 5pm.