The Partenopei only managed to test Udinese goalkeeper Daniele Padelli once in the 90 minutes in a match that lacked action by either goal mouth.
Napoli has endured a recent slump, having scored only once in its four-game winless streak in all competitions, and it took Walter Mazzarri's side until the 36th minute to muster the game's only shot on target. Marek Hamsik was looking to cap his 250th Napoli appearance with a goal, but the Slovakian was denied when his header from Pablo Armero's left-wing cross was smartly beaten away by Daniele Padelli.
In a scrappy first half devoid of presentable goalscoring opportunites, the Zebrette had the chance to open the scoring two minutes before halftime when Antonio Di Natale seized onto Emmanuel Agyemang-Badu's neat slide pass, but the 35-year-old captain could only fired his left-footed effort over the crossbar.
Mazzarri knew that his side could ill-afford to drop any more points in the Scudetto race and he cut a frustrated figure on the sidelines, urging his side to push forward. Hamsik witnessed his ambitious volley flash wide of Padelli's goal before Lorenzo Insigne's goal-bound effort was deflected inches past the post as Napoli strived to break the deadlock.
The 51-year-old coach was then left seething when Armero went tumbling in the penalty box under a challenge from Dusan Basta, but referee Antonio Damato adjudged that the Colombian wingback had dived and duly cautioned the former Udinese star.
The visitors were beginning to take control of the contest, and it looked as though they would open the scoring when Armero found space in behind Basta but his cutback was fed slightly behind Edinson Cavani, who could only steer the ball wide of the left-hand post.
Mazzarri threw on Goran Pandev and Juan Zuniga in a bid to snatch a late winner, but he watched his side fail time and time again to break down a resilient Zebrette defense and the game finished all square.
Napoli faces a potential title-decider when it entertains table-topping Juventus at Stadio San Paolo on Friday.