Fiorentina came back from Naples with a single point having failed to break down Napoli's resistance.
Sebastian De La Fuente's laid siege to the hosts' goal in the second half but were thwarted by Napoli keeper Doris Bacic and had a penalty appeal turned down after a handball in the box went unseen.
Next Sunday, AC Milan will visit Viola Park for a 12:30 kick-off.
Napoli 0-0 Fiorentina (HT 0-0)
NAPOLI FEMMINILE: Bacic, Lundorf, Sandvej, Sliskovic, Martinovic, Muth, Di Giammarino (Giai 90+1), Bellucci, Moretti (Sciabica 46), Pettenuzzo (C), Giordano (Novellino 83).
Subs not used: Beretta, Jelcic, Fracaros, Adugbe, D’Angelo, Langella.
Coach: Salvatore Mango.
ACF FIORENTINA: Fiskerstrand, Toniolo (Johannsdottir 76), Tortelli (C), Filangeri, Faerge, Severini (Pastrenge 76), Catena (Lundin 83), Snerle (Bredgaard 67), Boquete (C), Bonfantini, Janogy.
Subs not used: Durante, Breitner, Longo, Erzen, Cherubini, Bettineschi.
Coach: Sebastian De La Fuente.
Booked: Tortelli, Severini, Bacic, Sliskovic, Pastrenge, Salvatore Mango.