Argentinian Dybala followed his midweek Champions League victor over Tottenham with a match-clinching double, as Massimiliano Allegri's men moved two points clear of Napoli.
Paulo Dybala stole the headlines by bagging a brace on the day, while Gonzalo Higuain missed a first-half penalty.
"I'm happy to have helped the team with my goals".
Paulo Dybala broke the deadlock in the 20th minute, curling a trademark free kick into the top corner.
Higuain made up for his error by setting up Dybala's second goal four minutes after the break.
Dybala missed a great late chance to complete a hat trick when he fired wide, but Juve, which hosts Atalanta in a rearranged match Wednesday, was never in danger of failing to close out the win.
Dybala has scored four goals from his last three matches.
Napoli's in-form strike force of Dries Mertens and Lucas Insigne struggled to create anything going forward for the hosts.
Napoli, which lost at home to Roma last weekend, nearly fell to a second successive defeat as Inter went closest to breaking the deadlock when Milan Skriniar headed a free kick off the right post early in the second half.
The match started with a poignant tribute to Fiorentina captain Davide Astori following his tragic death.
Andre Silva struck in the fourth minute of second-half stoppage time to seal a 1-0 win over AC Milan on Sunday evening.
Ciro Immobile grabbed Lazio a 2-2 draw at Cagliari with a stunning equaliser in the fifth minute of injury time. There is one draw, the one from this season when Inter and Napoli drew 0-0 in Naples.