Rafael Benitez's Napoli made it four successive wins in all competitions since their loss to Roma last month with a 2-1 home triumph over Catania.
All three goals came in the opening 25 minutes with Jose Maria Callejon (15) and Marek Hamsik (20) putting Napoli in control before Lucas Castro quickly pulled a goal back.
Catania could not find an equaliser though as Napoli remained narrowly ahead of Juventus, who also boast 28 points from 11 games after beating Parma 1-0 away from home.
Paul Pogba scored the only goal as Juventus enjoyed a winning start to what could prove to be a key week as they play host to Real Madrid in the Champions League on Tuesday before welcoming Napoli in Serie A next weekend.
Both Napoli and Juve are two points behind Roma as the capital city club look to make it 11 successive league wins this season on Sunday.
In Saturday's other game, Fiorentina climbed into the top four with a 2-0 win over AC Milan that is likely to heap more pressure on Rossoneri coach Massimiliano Allegri.
Juan Vargas gave the Viola the lead in the 27th minute with a deflected free-kick before Borja Valero wrapped up victory midway through the second half with a tap in.
The result was another blow to Milan, who are now winless in their last four games in all competitions and have won just two of their past nine league games to lie 10th in the standings. The defeat leaves them 16 points adrift of third-place Juventus and the last Champions League qualifying spot.