The Real Madrid forward scored a penalty as the European champions came from behind to win 2-1 in Bulgaria, while the Reds slumped to defeat
The reigning European champions went behind to a Marcelinho strike after six minutes in Sofia but Ronaldo lead a fight back to help secure a late victory.
The Fifa World Player of the Year had a penalty saved on 11 minutes, but equalised from the spot 14 minutes later.
European minnows Ludogorets fought hard to hold onto the draw but Karim Benzema eventually slotted home the winner for Carlo Ancelotti’s Group B leaders 13 minutes from time.
After the match, Ronaldo praised their hosts but said the win proved Real’s big-team mentality.
“They are a good team and with their fans behind them they got extra energy” he said. “It’s really important that we won this game, but it was a tough challenge.
“Games like these happen and big teams must find an answer to such situations. I think we showed tonight we are one of them.
“But there is no perfect team in the world and so you always have to be focused – especially in the Uefa Champions League. I think it’s a deserved win. We had a lot of chances and they had not so many good ones. As Liverpool lost today this win could be a big moment.”
Real Madrid’s next two matches in the Champions League are both against Liverpool, who lost 1-0 in Basel on Wednesday, first at Anfield and then in the Santiago Bernabeu.
Los Blancos lead Group B on six points, with Liverpool and Basel on three and pointless Ludogorets Razgrad bottom.