Alvaro Morata was relegated to the substitutes' bench as Juan Cuadrado, Dejan Kulusevski, Weston McKennie and Federico Chiesa returned from Sunday's loss to Inter Milan in the Derby d'Italia.
Juventus made a bright start, however Napoli had the first real chance midway in the first half when a teasing ball from Lorenzo Insigne bounced off Andrea Petagna and away from goal.
More threats came from Petagna following 31 minutes when his header from a cross by Diego Demme brought a superb save from Wojciech Szczesny.
Ronaldo looked to bring his side to life a little later from a threatening ball around the area, but was stopped in his tracks before he shaved the far post with a deft strike later on.
Chiesa was withdrawn at the start of the second half with Federico Bernardeschi introduced as Juve made the first substitution of the match.
Bernardeschi nearly made an immediate impact when he poked a cross from McKennie towards goal only for Napoli goalkeeper David Ospina to scurry back and bundle off the line.
However, Juventus managed to hit the front albeit deservedly midway in the second half through a close-range finish from Ronaldo following a loose ball to become the highest scorer in football.
Gennaro Gattuso's side were given a chance to draw level from the spot 12 minutes from time after McKennie upended Dries Mertens in the area, but Insigne fired wide.
The Partenopei were put out of their misery when substitute Morata pounced on a ball from Cuadrado following a counter-attack to slot into an empty net, as Juve claimed the crown.