The champions led through Rodrigo Bentancur’s excellent 18-yard strike after a one-two with Paulo Dybala.
Giorgio Chiellini scored his first goal in 18 months – a fortunate effort which keeper Alban Lafont pushed into the air, before it landed in his net.
And Ronaldo scored his 10th Serie A goal with a penalty after a handball.
The £99m summer signing from Real Madrid is the joint top scorer in the Italian top flight with Genoa’s Krzysztof Piatek.
The last Juventus player to score 10 goals in the first 14 games of his maiden Serie A season was Wales’ John Charles in 1957.
Juve, who are going for their eighth consecutive Italian title, have won 13 of their 14 league games.
Second-placed Napoli visit Atalanta on Monday.