The former Manchester United man will look to add another chapter to his extraordinary career by winning the Champions League for a fourth time.
Victory over city rivals Atletico Madrid in tonight's semi-final first leg will push Real one step closer to Cardiff.
And all eyes will be on Ronaldo once again in a week where he broke Jimmy Greaves' all-time goalscoring record in Europe's top six divisions.
Real Madrid boss Zinedine Zidane admits he is jealous of Cristiano Ronaldo
"As a coach he is the best player I have had," said legendary former France midfielder Zidane. "I wasn't able to play with him, unfortunately – but I did play against him. His statistics are amazing.
"I played with the Brazilian Ronaldo, who was also an extraordinary player who scored a lot of goals. I'm jealous of them because I didn't have those numbers.
"I got a lot of assists but I just passed the ball and didn't have their goalscoring ability, so I never had the same feeling – that thrill of the ball hitting the net – as them. They are decisive players."
Portugal international Ronaldo has scored an extraordinary 41 goals in 44 appearances for club and country this season, including five times in the last Champions League round against Bayern Munich.
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This is the fourth season running where the Madrid clubs have faced each other in European competition with Real winning in each of the last three campaigns.. However Zidane was cautious about his side.
"We are not favourites, this is a semi-final and it's 50-50," he said. "We have to do the maximum to win the match and that's it. We have to think only in tomorrow's game and not in the second leg".
Atletico have been hit by a number of injuries with major concerns in defence, both Jose Gimenez and Juanfran Torres set to miss out.
They have though received a boost on the eve of the game with the announcement of Lucas Hernandez signing a new five-year deal.