Napoli survived a tense night at the Stadio Diego Armando Maradona, edging Cagliari 9–8 on penalties after a 1–1 draw to book their place in the Italian Cup quarter-finals.
Lorenzo Lucca had put the champions ahead with a 28th-minute finish, but Sebastiano Esposito levelled after the break to force spot-kicks, with Italian Cup rules sending the tie straight to a shoot-out.
Cagliari blinked first when Mattia Felici struck the crossbar, but David Neres failed to capitalise as his effort was saved by Elia Caprile.
The drama stretched deep into sudden death before Napoli goalkeeper Vanja Milinkovic-Savic made the decisive stop from Zito Luvumbo, allowing Alessandro Buongiorno to convert the winning penalty.
Napoli will face either Como or Fiorentina in the last eight.
Elsewhere, Atalanta thrashed Genoa 4–0, while Inter Milan eased past Venezia 5–1, with Marcus Thuram scoring twice. The round continues on Thursday as holders Bologna welcome Parma.