Sao Paulo - Maria Bueno, the Brazilian "queen" of tennis, who won three Wimbledon and four US championship singles titles, died Friday in Sao Paulo at age 78, the hospital where she was being treated said.
She had been suffering from mouth cancer since last year and was hospitalized in May.
Nicknamed the "Sao Paulo Swallow" for her ability to dominate the net, Bueno was a teen prodigy despite having no formal coaching, according to the International Hall of Fame, which she entered in 1978.
She swept the Brazilian scene, then the Caribbean circuit, and grabbed international attention by winning the Italian Championships in 1958, beating the best English and Australian players.
That same year she went on to win the Wimbledon doubles alongside American Althea Gibson. And although she once told reporters "I'm afraid of everyone I play," her glory days were only just beginning.
Bueno's death dominated Brazilian Twitter on Friday night, with tributes pouring in.
Brazilian President Michel Temer, writing on his official account, said Bueno "will always be remembered as the number one of tennis in the hearts of all Brazilians."
On and off the court, Bueno "always showed a lot of fight," Brazilian tennis player Bia Haddad said.
"She was a pioneer in our country, where few people knew the sport and at a time when everything was much more difficult," said tennis player Thomaz Bellucci.
Known for her stylishness and her exciting way of playing, she was the first South American woman to win the Wimbledon singles title.
One tennis writer, John Barrett, called her "the elegant queen of Brazilian tennis."
Her one major title of the open era, when big tournaments opened to professionals, was the 1968 US Open doubles alongside Australian legend Margaret Court.
Another doubles partner was Billie Jean King, with whom she won the Wimbledon title in 1965.
"In my era, tennis was totally amateur. I'd only take two rackets to a tournament and the prize for winning Wimbledon was a 15 voucher," she said in a 2015 interview with YouTube channel Esporte Ponto Final.
"But through sport I got things that money can't buy. I even met the pope and Princess Diana."
For years after retirement she was a commentator on Brazil's SporTV.
World number one in 1959, 1960, 1964 and 1966, Bueno was Brazil's best ever player, winning 19 Grand Slam titles. These included Wimbledon singles titles in 1959, 1960 and 1964, and the US National Championship -- precursor to today's US Open -- in 1959, 1963, 1964 and 1966.
She also got to the finals of the French championship in 1964 and the Australian in 1965.
Bueno was a consultant for several years for Sportv and commented on matches with Gustavo "Guga" Kuerten, the other Brazilian tennis legend.
Always smiling in her television appearances, Bueno continued playing until last year, when she was stricken by disease.