"This chapter is over," Ronaldo cryptically said on social media with a photo of him in an Al-Nassr shirt.
Ronaldo, the top scorer in this season's Saudi Pro League, has eight in seven appearances in this campaign's Champions League Elite, one short of joint-top scorers Riyad Mahrez, Salem Al-Dawsari, Anderson and Jasir Asani.
The 19-year-old forward, who trains daily alongside one of football’s all-time greats, is part of a promising Saudi Arabian generation aiming to make a statement on the global stage.
Al-Nassr remain in the third place with 54 points but they are now three points behind second-placed Al-Hilal and seven off leaders Al-Ittihad, who visit Al-Ahli on Saturday.
Cristiano Ronaldo's Saudi side Al Nassr were on Monday drawn against last season's runners-up Yokohama F-Marinos of Japan in the quarter-finals of the Asian Champions League.
Ronaldo, the Al Nassr captain, was reportedly rested for last week's goalless draw in the first leg in Iran, however returned to lead the side at Al Awwal Park.
Ronaldo turned 40 last week with his current contract due to end in June 2025.
Al Nassr captain Ronaldo had looked destined to endure a hugely frustrating game following a series of missed opportunities in the first half at Al Bayt Stadium.
The Portuguese star, without a goal in his past three appearances for the Saudi Arabian side, netted the second of the hosts' goals at Al Awwal Park in Riyadh.
Portugal captain Cristiano Ronaldo said his "work is done" in Europe, adding that he is relishing new challenges both on and off the pitch after being unveiled as a player of Saudi Arabian club Al Nassr on Tuesday.
Al Nassr coach Rudi Garcia said the signing of Cristiano Ronaldo was a big step forward for Saudi Arabian football after the Portuguese forward arrived in Riyadh ahead of his official unveiling on Tuesday.
Al Nassr's surprise capture of football superstar Cristiano Ronaldo is the latest in a string of high-profile sports acquisitions by oil-rich Saudi Arabia.
Portuguese superstar Cristiano Ronaldo arrived in Riyadh ahead of his grand unveiling before thousands of fans at Saudi Arabia's Al Nassr club on Tuesday, after sealing a shock move estimated at more than 200 million euros.
Cristiano Ronaldo on Friday signed for Al Nassr of Saudi Arabia, the club announced, in a deal believed to be worth more than 200 million euros.
Rene Higuita who enjoyed a madcap moment or two in his playing days, has taken to the swimming pool to celebrate his famous Wembley moment.
