Napoli was only able to reduce the deficit on Serie A leaders Juventus to six points as it was held to a 0-0 draw by Udinese at the Stadio Friuli on Monday night.
Chances were few and far between with Udinese rarely looking at risk of conceding, but seeming equally unlikely to score.
A late rally from Napoli was not enough for it to take more than a point back home as it lacked its usual shine on a disappointing night for Walter Mazzarri's men.
Lazio took advantage of that result to move to within five points of Napoli with a 2-0 win over Pescara, claiming victory with two fantastic goals from outside the box.
Stefan Radu opened his Serie A account in stunning fashion after 29 minutes, but not wanting to be outdone, Senad Lulic fired in an even better second five minutes later to earn Vladimir Petkovic's men the spoils.
Pescara made a game of it in the second half but was unable to find a route back into the contest as it remained in the bottom three, five points adrift of safety.