The Portuguese trickster scored from the spot as Real came from 1-0 down to beat Champions League newcomers Ludogorets Razgrad 2-1 in Bulgaria.
Ronaldo missed a penalty earlier in the game but made up for it by slotting home his second chance, with Karim Benzema netting the winner 13 minutes from time.
READ: Wednesday's Champions League wrap
The current Ballon d'Or title holder has now scored 69 goals in the Champions League and is closing in on Spain and club legend Raul Gonzalez's record of 71. Lionel Messi is on 68.
Ronaldo picked up an ankle knock late in the game but Los Blancos manager Carlo Ancelotti played down any injury fears.
"He has a bruised ankle. I don't think it's anything," Ancelotti told AS. "He's a little sore but it's nothing serious."
On the performance, Ancelotti added: "We had a lot of chances to score and we have to be more effective. But I'm satisfied. The start wasn't good and conceding again from a set-piece could have made things complicated. But the reaction was good.
"The team played well in attack and we're physically very good at the moment. We had many chances and could have scored at the end. We deserved to win. We're working to fix the set-pieces."