The hosts were first awarded a spot kick for handball in the first half and Ronaldo swept home the penalty.
Rodrigo Bentancur was fouled inside the box towards the end of the second half and Ronaldo again converted.
Matthijs de Ligt then headed in a third in injury time.
Ronaldo has now scored in nine successive Serie A games for Juventus, becoming the first player to do so since David Trezeguet in December 2005.
He has also scored 50 goals in just 70 appearances since joining the Italian giants in 2018.
The win strengthens Juventus’ place at the top of the table, with 54 points from 22 games – six clear of Inter Milan.