Several former world champions, including Muhammad Ali, on Monday paid their last respects to Joe Frazier, who was laid to rest in a private funeral in Philadelphia.The 67-year-old Frazier died last week after a short battle with liver cancer.The service in the Tabernacle Baptist Church in front of 4,000 people was led by Reverand Jesse Jackson, who said that Frazier remained the guy from the streets.\"Joe paid real dues and he\'s a guy who we can emulate - an ordinary Joe with extraordinary things. He will be remembered as a great boxing champion, as a great humanitarian,\" Jackson said.Ali, who was involved in three fights against Frazier, was one of the mourners at the funeral although he is suffering from Parkinson\'s disease.He briefly stood up at the funeral to pay his respect to Frazier.Also amongst the mourners at the funeral, at which Frazier was laid to rest in a white casket with the heavyweight title belt he retained after beating Ali in 1971 and a pair of boxing gloves on it, were boxing promoter Don King and former heavyweight champion Larry Holmes.\"Smokin\' Joe\" Frazier won Olympic gold in 1964 and claimed the world heavyweight title in 1970 over holder Jimmy Ellis.Ali was stripped of the title in 1967 for his refusal to fight in the Vietnam War, but was reinstated in 1971 to set up the trilogy of fights with Frazier which are among the most famous in the sport\'s history.The two met for the first time 1971 at Madison Square Garden in New York.The hyped title fight fully lived up to its billing of \"Fight of the Century,\" with Frazier flooring Ali in the 15th round en route to a unanimous points decision and Ali\'s first defeat.Frazier lost the world title 1973 to George Foreman in Jamaica for his first career defeat, and the second bout with Ali 1974 in points, again at Madison Square Garden.Their final fight, another title bout after Ali had beaten Foreman, was the \"Thrilla in Manila\" in the Philippines capital. That epic was stopped by Frazier\'s camp after the 14th round.Frazier later lost again to Foreman the next year, but is mostly remembered for his bouts with Ali. He retired in 1976, returned for one fight in 1981 and ended his career with a 32-4-1 record, his only defeats coming against Ali and Foreman.