Mazzarri's men fell to an unexpected defeat at the hands of the relegation candidates just days before their crucial clash against Bayern Munich in the Champions League
After a rather uneventful first half, Massimo Gobbi and Guiseppe Mascara traded goals in the second period, but just before the end of the match Francesco Modesto decided the tie with a strike from close range.
The game got off to a rather slow start as both team employed a rather defensive approach in the early minutes. Parma, however, created the more dangerous chances early on, as Sebastian Giovinco fired just wide from a free kick, while Sergio Floccari and Abderazak Jadid saw shots saved.
Napoli also stepped up a gear in the final minutes of the first period as Gokhan Inler saw a powerful drive saved by Antonio Mirante, and Christian Maggio had the fans holding their breaths as he received the ball just outside the six-yard box, but was dispossessed by Alessandro Lucarelli.
The game sprung into life in the second period as Marek Hamsik, Gokhan Inler, Ezequiel Lavezzi and Cavani all saw shots blocked or miss the target shortly after the restart as Napoli were tightening their grip on the contest.
Parma, however, took advantage of the hosts' reckless attacking and managed to open the scoring in the 57th minute through Gobbi, who powered a shot past De Sanctis after a sublime backheel by Floccari.
Napoli doubled its efforts in search for an equalizer, and finally got its goal in the 76th minute, when Mascara finished off a fine team move to claw one back for Walter Mazzarri's side.
The hosts' joy did not last long, however, as shortly after the ex-Catania man's strike Modesto hammered home the winner from close range following a cross by Giovinco to seal the three points for Franco Colomba's men.
Cavani was unfortunate to hit the right post from a tight angle moments before the final whistle as Napoli just ran out of luck, and had to accept defeat.
Following tonight's result, Napoli are third in the standings with 10 points, while Parma are seventh with nine. Walter Mazzarri's men visit Cagliari in eight days in the next Serie A game, while Parma hosts Atalanta on the same day.