Ibiza, Spain - Motorcycling legend Angel Nieto has died aged 70, eight days after being involved in a quad crash.
The official site of the MotoGP motorcycling world championship said on Thursday: "The 13-times world champion - whose superstitiously always referred to his titles as 12+1 - was a motorcycle racing legend and a key figure in establishing Spain as a world-beating force in Grand Prix motorcycle racing."
Nieto was riding a quad on Wednesday last week when he "had an accident with a tourism vehicle", police said at the time. He was rushed to hospital in a serious condition, where he remained in intensive care, but his condition deteriorated before he passed away on Thursday.
Nieto is second on the all-time list of most motorcycling world championship titles, two behind Italian great Giacomo Agostini. Only "Ago" and current great Valentino Rossi have bettered his tally of 90 Grand Prix wins.
Reigning world MotoGP champion Marc Marquez was among the first to pay tribute to Nieto, who also scored 139 podium finishes in his career.
Marquez tweeted: "Thanks for everything you have taught us! Rest in peace maestro."
Football giants Real Madrid also remembered Nieto. The European champions tweeted: "Real Madrid are deeply saddened by the passing of Angel Nieto and extend their condolences to his family and friends at this difficult time.
"Spanish sport has lost a true legend who will never be forgotten. His extraordinarily successful career and exemplary behaviour have made him an eternal idol for motorcycle fans around the world and for sport in general."
Nieto competed in his first Grand Prix at just 17 in 1964 before going on to win six world titles in the 50cc category and seven in the 125 division. He retired, aged 39, two years after his final world championship in 1986.
Nieto recalled in an interview with Spanish broadcaster TVE: "The day I decided to stop racing I was 39, it had been two years since I had won the last world championship and I was in Austria.
"The mechanics left and I thought 'what am I doing here, I said this is it, the winning spirit I always had, had come to an end. When it was over, I got down, I said I'm going home, and it was over."
However, he still remained involved in the sport as team manager when Emilio Alzamora won the 125cc world championship in 1999.
Spanish prime minister Mariano Rajoy tweeted. "My condolences to the family of Angel Nieto, a legend of motorcycling and Spanish sport, who won the respect and love of the fans."