After boxing legend, cultural icon, and civil-rights activist Muhammad Ali passed away late Friday evening at the age of 74, the rest of the boxing world collectively mourned. In a statement, George Foreman, Ali's opponent in the famed "Rumble in the Jungle" match, described the late boxer as "one of the greatest human beings I have ever met." Alongside a picture of his younger self seated with Ali, Mike Tyson tweeted: "God came for his champion. So long great one." Oscar de la Hoya, a fellow ex-world champion, remembered Ali as "a legend who transcended sport and was a true champion for all." "He stood for something that he really believed in," five-time champion Evander Holyfield said. Famed fight promoter Don King lamented, "It's a sad day for life, man." Manny Pacquiao tweeted a dramatic photo of Ali, with the caption: "We lost a giant today. You will always be [greatest of all-time]."