Manny Pacquiao, one of the greatest boxers of his generation, led Philippine tributes to Muhammad Ali on Saturday, as he joined his fellow countrymen in mourning the American legend's death.

"We lost a giant today," Pacquiao, the only man in boxing history to win world titles in eight different weight divisions, said in a statement.

"Boxing benefited from Muhammad Ali's talents but not nearly as much as mankind benefited from his humanity. Our hearts and prayers go out to the Ali family," Pacquiao added.

The boxing-crazy Asian nation was the scene of one of Ali's greatest triumphs, the epic "Thrilla in Manila" on October 1, 1975, when he scored a 14th round technical knockout of Joe Frazier in their third and last fight.

PHOTO GALLERY: Muhammad Ali: You're 'The Greatest' (1942-2016)

A Manila shopping mall, built near the coliseum that hosted the bout, unfurled a large poster of Ali on Saturday in tribute.

Hours before the family announced Ali's death, Pacquiao, who won a seat in the country's Senate in last month's elections, posted Ali's picture in his Instagram account and urged fans to "keep Muhammad Ali in your thoughts and prayers".

President Benigno Aquino's spokesman Herminio Coloma told AFP: "Muhammad Ali is a legendary athlete who touched the lives of people from all over the world, including Filipinos who witnessed the 'Thrilla in Manila'."

"We mourn the passing of 'the greatest' who floated like a butterfly but stung like a bee," Philippine Olympic Committee spokesman Joey Romasanta -- who keeps a poster of the "Thrilla in Manila" fight in his office -- told AFP in a statement.

"He was an icon and an idol to several generations," said Ed Picson, the executive director of the Philippines' amateur boxing federation, who cheered for Ali more than 40 years ago at the Manila bout.

"As a boxer he dazzled, mesmerised and inspired awe. There will never be anyone like him. He was, is and will always be the greatest," Picson told AFP.