“It’s not the end of my career to come to Saudi Arabia. This is why I change and, to be honest, I’m really not worried about what people say,” Ronaldo said.
“In Europe my work is done... I had many offers in Europe, many in Brazil, Australia, the US, even in Portugal,” he added. “Many clubs tried to sign me but I gave my word to this club.”
The packed, 25,000-capacity stadium erupted when Ronaldo, dressed in Al Nassr’s yellow and blue kit, walked on the pitch, saluting the crowd as fireworks and floodlights flashed around him.
His girlfriend Georgina Rodriguez, wearing the traditional black abaya or all-covering robe worn by most Saudi women, followed at a distance along with Ronaldo’s children.
“I’m a unique player. It’s good to come here, I broke all the records there (in Europe) and I want to break a few records here,” Ronaldo said earlier.
“I’m coming here to win, to play, to enjoy, to be part of the success of the country and culture of the country,” he added.
Ronaldo joins the nine-time Saudi champions just weeks after his departure from United following a TV interview where he slammed the club and coach Erik ten Hag.
Al Nassr, the nine-time Saudi league champions, represent a significant drop in standard for the Portuguese forward who spearheaded title-laden campaigns with United, Real Madrid and Juventus.
Oil-rich monarchy Saudi Arabia, which has been snapping up sports assets as part of a drive to soften its austere image, is often accused of “sportswashing”, or using sport to distract attention from human rights controversies.
Ronaldo arrives just weeks after the World Cup in neighbouring Qatar, and as Saudi Arabia considers a joint Asia-Africa-Europe bid to host football’s biggest tournament with Egypt and Greece.
Well before his arrival, supporters carrying yellow “Ronaldo 7” flags and blue-and-yellow Al Nassr scarves turned up at the stadium, some of them looking for tickets.
Adam Seddik, an Al Ittihad fan from Jeddah, said he drove 900 kilometres (560 miles) to Riyadh to witness the spectacle.
“His presence will elevate the Saudi league value and its viewership,” said Seddik.
“He is the greatest player in the world.”
Excitement is at fever-pitch over the arrival of Ronaldo, the highest-profile player to come to Saudi Arabia, the Gulf or any country in the Asian confederation.
Fans queued down the street to buy Ronaldo’s Al Nassr shirt with his trademark number seven, and Al Nassr’s Instagram page gained millions of new followers after his signing was made public.
Ronaldo’s signing comes against the backdrop of a Saudi push into sports including golf, boxing, tennis and F1 as well as football, following the takeover of English Premier League club Newcastle United last year.
Saudi Arabia, led by de facto ruler Crown Prince Mohammed bin Salman -- Ronaldo’s contemporary at 37 -- will host upcoming editions of the Asian Games and Asian Winter Games, as well as football’s men’s and women’s Asian Cups.