The genial Dundee was best known for being in Ali's corner for almost his entire career, but those in boxing also knew him as an ambassador for boxing and a figure of integrity in a sport that often lacked it.
He died with his family surrounding him, said son, Jimmy Dundee, but not before being able to attend Ali's 70th birthday bash in Louisville, Ky., last month.
"It was the way he wanted to go," Jimmy Dundee said. "He did everything he wanted to do."
A master motivator and clever corner man, Dundee was regarded as one of the sport's great ambassadors. He was inducted into the International Boxing Hall of Fame in 1994 after a career that spanned six decades, training 15 world champions, including Leonard, George Foreman, Carmen Basilio and Jose Napoles.
But he will always be linked to Ali as one of the most successful fighter-trainer relationships in boxing history, helping Ali become the first to win the heavyweight title three times. The pair would travel around the world for fights to such obscure places as Ali's October 1974 bout in Zaire against Foreman dubbed "The Rumble in the Jungle," and Ali's third fight against Joe Frazier in Quezon City, Metro Manila, Philippines, called by promoters as the "Thrilla in Manila."
"I just put the reflexes in the proper direction," Dundee said in a 2005 interview with The Associated Press.
Their partnership began in Louisville, Ali's hometown, in 1959. Dundee was there with light heavyweight Willie Pastrano when the young Ali, then known as Cassius Clay, called their room from a hotel phone to ask if he could have five minutes. Clay, a local Golden Gloves champion, kept asking the men boxing questions in a conversation that lasted 3½ hours, according to Dundee's autobiography, "My View From the Corner: A Life in Boxing."
After Ali returned from Rome with a gold medal at the 1960 Olympics, Dundee ran into him in Louisville and invited him to come to Miami Beach to train. Ali declined. But that December, Dundee got a call from one of Ali's handlers, seeking to hire Dundee. After Ali won his first pro fight, Dundee accepted.
He helped Ali claim the heavyweight title for the first time on Feb. 25, 1964, when Sonny Liston quit on his stool after the sixth round during their fight in Miami Beach.
In an age of boxing when fighter-manager relationships rarely last, Dundee and Ali would never split.
When Cassius Clay angered white America by joining the Black Muslims and become Muhammad Ali, Dundee never wavered. When Ali defied the draft at the height of the Vietnam war, losing 3 1/2 years from the prime of his career, Dundee was there waiting for the heavyweight's return. And when Ali would make bold projections, spewing poetry that made headlines across the world and gave him the nickname "The Louisville Lip," Dundee never asked him to keep quiet.
"Through all those days of controversy, and the many that followed, Angelo never got involved," Ali wrote in the foreword to Dundee's book. "He let me be exactly who I wanted to be, and he was loyal. That is the reason I love Angelo."
Born Angelo Mirena on Aug. 30, 1921, in south Philadelphia, Dundee's boxing career was propelled largely by his older brother, Chris, a promoter. After returning from World War II - "We won, but not because of anything I did" - he joined Chris in the boxing game in New York, serving as his "go-fer" and getting the tag "Chris' kid brother." Angelo and Chris followed another brother Joe, who was a fighter, in changing their surname to Dundee so their parents wouldn't know they worked in boxing.
AP Sports Writer Antonio Gonzalez contributed to this report.