Juventus forward, Cristiano Ronaldo netted his eighth goal in eight games in a row, but it was not enough to help Maurizio Sarri’s men after Piotr Zielinski and Lorenzo Insigne put Napoli 2-0 ahead on Sunday.
It took Ronaldo’s tally for the season up to 17 goals.
However, Lazio’s Ciro Immobile is presently the top goal scorer in the Serie A with 23 goals.
Inter Milan’s Romelu Lukaku failed to find the back of the net, as they were held to a 1-1 draw by Cagliari.
Serie A top scorers:
23 goals: Ciro Immobile (Lazio)
17 goals: Cristiano Ronaldo (Juventus)
14 goals: Romelu Lukaku (Inter Milan)
13 goals: João Pedro (Cagliari), Josip Ilicic (Atalanta)
12 goals: Luis Muriel (Atalanta)
11 goals: Lautaro Martínez (Inter Milan)
10 goals: Luis Muriel (Atalanta)
9 goals: Andrea Belotti (Torino), Domenico Berardi (Sassuolo), Edin Dzeko (Roma)
8 goals: Francesco Caputo (Sassuolo), Andrea Petagna, (SPAL)
7 goals: Arkadiusz Milik (Napoli), Andreas Cornelius (Parma), Robin Gosens (Atalanta), Duván Zapata (Atalanta)
6 goals: Joaquín Correa (Lazio), Alejandro Gómez (Atalanta), Marco Mancosu (Lecce)
5 goals: Gonzalo Higuaín (Juventus) Christian Kouamé (Genoa), Riccardo Orsolini (Bologna), Paulo Dybala (Juventus), Radja Nainggolan (Cagliari), Dejan Kulusevski (Parma)