|Ronaldo at his best was an unstoppable force for Brazil and a host of top clubs [GALLO/GETTY]
Three-time FIFA World Player of the Year Ronaldo, whose goalscoring genius led Brazil to the 2002 World Cup title, has confirmed his retirement at the age of 34.
The emotional Corinthians striker announced his decision at a press conference in Sao Paulo.
"I'm stopping my career as a professional footballer," he said, his voice breaking.
"It's been a beautiful, emotional, marvellous career.
"These last two years, I've had a long series of injuries, from one side to the other, one leg to the other, one muscle to the other.
"It's been a beautiful, emotional, marvellous career"
Ronaldo, Brazilian World Cup-winning striker
"The pain pushed me to think about the end of my career."
Ronaldo also revealed that he suffered from a thyroid problem that had made it difficult to control his weight.
"Four years ago, in Milan, I discovered that I suffered from an under-active thyroid that slowed down my metabolism and that to control it, I had to take hormones that weren't authorised in football as they were considered a form of doping," he said.
"Lots of people must regret having made jokes about my weight. But I feel no anger towards anyone."
Having earlier indicated that he hoped to play on until the end of the year, injuries and Corinthians' early elimination from the Copa Libertadores prompted him to bring forward his retirement.
When he was fit, Ronaldo was unstoppable.
During a glittering 14-year spell in Europe, Ronaldo scored goals at a prolific rate for PSV Eindhoven, Barcelona, Inter Milan, Real Madrid and AC Milan, before returning to Brazil in 2009.
He won the World Cup with Brazil in 2002 and became the leading scorer in World Cup finals tournaments when he scored his 15th goal at the 2006 tournament in Germany.
|Ronaldo holds up a Corinthians shirt as he announces his retirement in Sao Paolo [AFP]
He was twice named European Footballer of the Year, in 1997 and 2002, and finished his international career with 62 goals in 97 appearances.
Widely regarded as one of the greatest players of all time, 'El Fenomeno' (The Phenomenon) won the World Cup with Brazil for the first time in 1994, though on that occasion the 17-year-old was part of the squad and did not play.
In 1998, he was among the losing finalists, beaten 3-0 at Stade de France by a rampant French side that included the inspirational Zinedine Zidane.
Brazil's star striker suffered a convulsive fit on the eve of the match and was removed from the starting line-up.
In a dramatic changing-room re-shuffle, he was reinstated just before kick-off but was a shadow of the intimidating forward who had scored four goals in the run-up to the final.
But the 2002 tournament was where he made history.
Shrugging off injury in the tournament, which was hosted by Japan and South Korea, he played a key role in helping Brazil to the trophy, scoring both goals in his country's 2-0 win over Germany in the final in Yokohoma.
His private life got plenty of publicity, whether he liked it or not. He first marriage was with footballer Milene Rodrigues, whose talent of keeping a ball in the air had earned her the nickname "the Queen of the Keep-ups", and they had a son, Ronald.
He later married Daniela Cicarelli at a French chateaux in 2005, but they split up three months later.
The most publicised incident came three years ago when police said Ronaldo went to a love motel in Rio de Janeiro with three call girls, only to find out they were transvestites.
"Behind the personality which I carry, I'm a normal person and I have my weaknesses and my fears," he said.