At the top of each half, Juventus were awarded penalties after var checks and each times Ronaldo was able to convert.
The first goal made it 9 Serie A games in succession within which the Portuguese have netted.
Matthijs de Ligt arrived on the act too, along with his late strike adding some gloss to the scoreline of what was a good game for long spells.
The result puts the pressure on inter Milano to reply later within the day.
Antonio Conte’s side visits Udinese, seeking to cut the gap back off to 3 points. Meanwhile, La Viola remains down in fourteenth place, albeit well afar from any relegation worries.