A week after defeat at home to Parma, the Partenopei could only manage a scoreless draw against the Rossoblu and, in truth, were somewhat lucky to have escaped with a point
In an exciting opening period, Nene and Radja Nainggolan were both denied by the crossbar, while Mario Santana struck a post from point-blank range.
Neither side were able to break the deadlock, though, as Cagliari were held to a goalless draw at home for the third successive game.
Both sides played their part in a lively opening at the Sant’Elia, with the recalled Andrea Dossena going close with a left-footed effort for the visitors before Nene drew a fine save from Morgan De Sanctis at the other end.
Michele Canini then flashed a header wide of the Napoli goal after the first corner of the game 15 minutes in. Cagliari went even closer to opening the scoring midway through the first half, when Nene rose highest to meet a free-kick from the left-hand side only to see his well-directed header drop agonisingly on to the top of the crossbar and then out of play.
If the Brazilian had been unlucky, Santana was just downright wasteful when the ball dropped to him completely unmarked on the edge of the six-yard box 33 minutes in, the Argentine spinning nicely onto the ball but then smashing it against the left upright with the goal at his mercy.
Santana’s profligacy was almost immediately punished but Cagliari were again cruelly denied by the crossbar when Nainggolan demonstrated terrific technique in unleashing a stunning half-volley from the edge of the box.
Unsurprisingly, Napoli boss Walter Mazzarri did not wait long before throwing Marek Hamsik into the fray, the Slovak coming on seven minutes into the second half for the unusually ineffective Ezequiel Lavezzi. The Argentine's whose most noteworthy contribution to the game had been a clumsy first-half challenge on Davide Astori which had forced the Cagliari defender off through injury.
Hamsik fared not better than Lavezzi, though, and it was Cagliari who like the slightly more likely scorers in a rather turgid second period, as Thiago Ribeiro twice saw shots blocked by Salvatore Aronica. However, Napoli had the best chance to nick it but Christian Maggio shot tamely at Michael Agazzi after cutting inside onto his right foot.
Napoli's title aspirations have taken another blow after failing to win, as the battle for supremacy at the summit of Serie A intensifies.