On 11 June, Manchester United accepted an unconditional offer of £80 million from Real Madrid for Ronaldo after it was revealed that he again had expressed his desire to leave the club. It was confirmed by a representative of the Glazer family that the sale was fully condoned by Ferguson. When Ronaldo had eventually completed his transfer to Real, he expressed his gratitude towards Ferguson for helping him develop as a player, saying, "He's been my father in sport, one of the most important factors and most influential in my career."
On 26 June 2009, Real Madrid confirmed that Ronaldo would join the club on 1 July 2009, after agreeing terms and signing a six-year contract. Ronaldo's contract is worth €11 million per year and it has a €1 billion buy-out clause. He was presented to the world media as a Real Madrid player on 6 July, where he was handed the number 9 jersey. The shirt was presented to him by Madrid legend Alfredo di Stéfano. Ronaldo was welcomed by 80,000 fans at his presentation at the Santiago Bernabéu Stadium, surpassing Diego Maradona's record of 75,000 fans when he was presented in Italy, after he was transferred from Barcelona to Napoli in 1984.
Ronaldo made his Madrid debut on 21 July in a 1–0 win over Shamrock Rovers. His first goal came one week later on a penalty in Madrid's 4–2 LDU Quito. On 29 August, Ronaldo capped his La Liga debut with a goal, scoring Real's
second from the penalty spot in a 3–2 home win against Deportivo La Coruña. On 15 September, Ronaldo scored his first Champions League goals, both on free kicks, against Zürich in a 5–2 win. He broke a Madrid club record when he scored in a league match against Villarreal and thus became the first ever player to score in his first four La Liga appearances.
An ankle injury suffered on 10 October, while Ronaldo was on international duty with Portugal against Hungary, kept him out until 25 November, which in turn caused him to miss both of Madrid's Champions League group stage matches against Milan. Ronaldo made his first post-injury start in a 1–0 El Clásico defeat to Barcelona on 29 November. On 6 December, he was sent off for the first time in his Madrid career in Madrid's 4–2 victory against Almería, a