Cristiano Ronaldo and Angel Di Maria shared a dressing room for four years at Real Madrid. The Argentine forward recently recalled an incident from their time together in the Spanish capital when he invited the Portuguese superstar to his birthday party. Di Maria said he was surprised to see Ronaldo's level of humility."I invited Cristiano to my first birthday party that I had in Madrid," Angel Di Maria reflected on the incident. "I didn't think he'd come, but he messaged to say he was. And he ended up sitting down with my friends and chatting as if they were anyone. That surprised me."Throwback to Di Maria's ridiculous rabona assist for Cristiano Ronaldo 😱pic.twitter.com/K2CBciFCW5— Goal (@goal) May 18, 2020The Argentine added: "On the pitch, he [Ronaldo] always wants to be number one. Off the pitch, he is a different class."Angel Di Maria met Cristiano Ronaldo at Real Madrid in the summer of 2010 following a €30 million transfer from Benfica. He spent four trophy-laden years with the Portuguese at the Santiago Bernabeu before leaving for Manchester United in 2014.The 33-year-old made 190 appearances for Los Blancos during his spell in the Spanish capital, with a return of 36 goals and 85 assists.Cristiano Ronaldo also left Real Madrid four years after Di Maria's departure, as he completed a massive €100 million to Juventus in the summer of 2018.Welcome 𝗵𝗼𝗺𝗲, @Cristiano 🔴#MUFC | #Ronaldo— Manchester United (@ManUtd) August 27, 2021Ronaldo spent three years in Turin, recording 101 goals and 22 assists to his name in 134 games. The 5-time Ballon d'Or winner decided to part ways with the Italian giants this summer, sealing a €20 million transfer to Manchester United last month.Cristiano Ronaldo with a new challenge in the Premier LeagueCristiano Ronaldo left Juventus for Manchester United this summerAt 36 years of age, most footballers would've either hung their boots or moved to less competitive leagues. But Cristiano Ronaldo is still focused on taking up huge challenges.The attacker has returned to the Premier League, widely considered the most competitive league in Europe, ahead of the 2021-22 campaign. Ronaldo is expected to lead Manchester United's charge for silverware this season.The Portuguese will make his first appearance for the Red Devils this season after the conclusion of the international break. Ronaldo's debut is expected to take place during Manchester United's clash against Newcastle United at Old Trafford on September 11.