Fresh from his double over Inter Milan in the Coppa Italia semi-finals first-leg on Tuesday, Ronaldo partnered Alvaro Morata up top with Wojciech Szczesny back in goal.
Ronaldo continued from where he left off in midweek when he got on the end of a ball on the inside of the area 13 minutes gone to fire in the opener from a promising area.
It should've been two for the evergreen forward midway in the first half, but he nestled the crossbar after getting on the end of a perfect delivery from Morata.
Paulo Fonseca's side started to get into gear before halftime and came close to draw level with a header from Gianluca Mancini following a corner-kick by Jordan Veretout.
Ronaldo looked to give Juve a second in the closing minutes after he got behind Marash Kumbulla to set up Morata from close-range, but Roma goalkeeper Pau Lopez parried expertly.
Fonseca's side emerged for the second half confident and a smart effort from range by Henrikh Mkhitaryan brought a strong save off goalkeeper Szczesny.
Veteran striker Edin Dzeko, Carles Perez and Amadou Diawara all came on for the Giallorossi on 62 minutes in attempt to grab the equaliser.
It didn't arrive though after a cutback from the right-side by Dejan Kulusevski saw Roger Ibanez slot into his own net to put Juventus in firm control with 20 minutes left on the clock.
The Giallorossi hoped for a consolation towards full-time with a glancing header from Dzeko, but it wasn't forthcoming as Juve ran out 2-0 winners to go ahead of Roma in third spot.