The Portugal star scored an acrobatic volley in the second half of Madrid's 3-0 win in Turin on Tuesday, having put his side ahead just three minutes into the match.
Marcelo added a third following Paulo Dybala's red card to give the Champions League holders a commanding lead in the quarter-final.
Barzagli felt Juve perhaps deserved a better result given their good performance in the first hour, but he could only admire Ronaldo's finish.
"It was a PlayStation goal," he told Mediaset Premium. "When you play against one of the strongest in the world, you need perfection.
"As soon as you leave him something, he punishes you. He made up a goal that will go down in history. It's too bad it came against us.
"We perhaps deserved something more but we also risked conceding other goals. We accept this defeat and move on.
"When you score so many goals in the Champions League, it shows it's not just a problem for us. He's become lethal. He makes a thousand movements and always gets a goal.
"You can't do anything about it and the fans applauded him. It was perfect technique because, when you're upside down, you're not always able to hit the ball with power."
Barzagli was prepared to take the blame for Ronaldo's first goal, though, in which the 33-year-old prodded home after being picked out by Isco's low cross.
"I take the responsibility on myself," said the defender. "I was following [Karim] Benzema and [Giorgio] Chiellini had asked me to mark the near post."