Walter Mazzari's Napoli were not at their best but goals from the impressive Marek Hamsik and Paolo Cannavaro were enough to put them level on 49 points with the champions who travel to Chievo on Sunday.
Catania remained seventh on 35 points but Rolando Maran's team could count themselves unlucky with a couple of decisions, in particular when Juan Zuniga handled the ball in his own area with 35 minutes gone and no penalty was given.
"We know league positions are won from battles like tonight's and you can't distract yourself by looking at the table," Mazzari told reporters.
"We can't let our guard down. We're still a bit inexperienced in the way we see out games and keep the ball, every now and again we make things complicated for ourselves and give the opposition a chance to harm us.
"We should have scored the third goal. If you don't do that then the match is always going to be open," added Mazzari.
Hamsik was the star performer for Napoli and grabbed his ninth league goal of the season.
The Slovakian international gave his nervy team the lead after 31 minutes, starting the move that eventually led to him tapping home Zuniga's mishit shot from close range.
Cannavaro made it 2-0 a minute before half-time, the captain breaking Catania's offside trap before netting his first league goal of the season from Hamsik's drilled low cross.
Former Argentina forward Maradona enjoyed a memorable seven-year spell with Napoli from 1984-91 and the club won their only two league titles in 1987 and 1990.
Catania were also unhappy with the decision to rule out Gonzalo Bergessio's goal two minutes into the second half, the striker being adjudged to have fouled Zuniga before heading in Alejandro Gomez's corner.
"You can't focus on these incidents. We're going to move forward without saying anything," said Maran.
Earlier, Torino stretched their unbeaten run to seven matches with an uneventful goalless draw at home to Sampdoria.
Torino are 12th on 28 points while Sampdoria are 13th, seven points clear of the drop zone.
