Heavyweight contender Ron Lyle (43-7-1, 31 KOs), who fought Muhammad Ali for the title in 1975 and later battled George Foreman, has died in Denver at age 70. A Salvation Army official in Denver says Lyle died Saturday from complications from a sudden stomach ailment. Details weren’t immediately available. Ron McKinney says Lyle retired last year from running the charity’s boxing program, called Red Shield Cox-Lyle Boxing, but had worked out at the gym every day. Lyle lost to both Ali and Foreman in the mid-1970s bouts. He tried unsuccessfully to schedule another fight with Foreman during a brief comeback in the 1990s.