The world's boxing greats paid their respects to the late Muhammad Ali, arguably the best known boxer in the world, after he passed away at the age of 74 last Friday due to a respiratory condition complicated by Parkinson's disease.

Christian Filipino boxer and politician Manny Pacquiao said in a statement, "We lost a giant today. Boxing benefited from Muhammad Ali's talents but not nearly as much as mankind benefited from his humanity."

Evander Holyfield, a five-time heavyweight champion known as the "Real Deal," posted photos of Ali and himself together on his Twitter account as he recalled happy memories with his good friend. "Remembering the good old days with Ali," Holyfield wrote. "RIP my brother; I will never forget you."

"Big George" Foreman, a two-time heavyweight champ, also paid his condolences to Ali's family on Twitter. "Hana Ali & the whole family, my heart goes out to you. Muhammad Ali has been a fine man. That will never die," he told them.

Controversial boxer Mike Tyson, who, just like Ali, converted to Islam at a young age, also wrote on Twitter, "God came for his champion. So long great one."

Meanwhile, evangelist Franklin Graham wrote on his Facebook page that the world has lost a champion. Even though many of his fights took place in the boxing ring, Ali also faced a lot of opposition outside the ring because of his outspoken views, he said. Although the Graham family is Christian while Ali was a Muslim, that did not stop them from being friends.

"I had the privilege of meeting him on several occasions, and he visited at my parents' home in Montreat, North Carolina,"  Graham. "Muhammad Ali's father brought him to visit my father Billy Graham because he was concerned over Ali's faith in Islam and was afraid that his son had been led astray. They had a great visit, and my father had prayer with him."