Ron Lyle and Rip Clark once were friends in Colorado's Canon City prison and they both boxed for the prison team. After his parole in 1969 Lyle started on a boxing career that would eventually put him into the ring with Muhammad Ali, fighting for the heavyweight championship of the world. And Vernon (Rip) Clark came along, as an assistant trainer to Lyle, and as a friend.

But somwhere along the way, Lyle, heavyweight contender, and Clark, assistant trainer, broke the thread of their common bond, and no longer called each other friend.

On New Year's Eve, Clark went to Lyle's split-level home in suburban Lakewood. Lyle apparently wanted to talk to Clark about money. The two men argued in Lyle's living room. There was a shot. It killed Clark.

The events that led to the death of Clark are unclear. Lyle, free on bond, is facing a second-degree murder charge. Lakewood police, who arrested Lyle, say only that Clark was killed by a single shot from a 9-mm handgun. They say that Lyle's brothers, Phil and Robert, his sister and several children were in the basement of the house, watching a basketball game on television.

Lyle has said that after the shooting he called his attorney, Walter Gerash, and then his neighbor, Lt. David Dial of the Lakewood Police Department, and told them that he shot Clark in self defense and that they were arguing about money. On Gerash's advice, Lyle has said nothing more.

Why did it happen? No one can say for sure. But friends of both Clark and Lyle portray the relationship between the two in different, and sometimes contradictory terms.

Friends of Clark, who was 39 and had a wife and a 3-year-old son, say that he was a good honest man, someone who told jokes a lot so that he could make others laugh. Friends of Lyle say that he, too, was a good, if temperamental, man.

Mike Hayes, now a stockbroker in Denver, was an important member of Lyle's entourage in May, 1975, when Lyle fought Ali for the title, when Clark and Lyle were friends. Hayes was vice president of the Denver Boxing Club, which owned Lyle's contract and promoted Lyle both as a fighter and as a personality.

"It's true, Lyle did owe money to Clark," Hayes said. "Clark was an excon like Ron. They met in prison and became best of friends. Rip loved him and even quit a job at $13,000 a year - and that's pretty good for a guy who was in prison - so he could join him as a trainer. Well, an assistant trainer, more of go-fer who would do anything for Ron. But Ron only paid him a little at the beginning, and then, for a weeks and weeks, he didn't pay him at all."

In March 1976, several months after Lyle lost by a knockout to and got along with us, me and Bill George Foreman, Lyle sued to get out of his contract with the Denver Boxing Club. The matter was settled out of court, and the club owner Bill Daniels, a Denver businessman, said that it was "probably the biggest heartbreak of my life. We were partners and I was his best friend . . . I don't know what happened between him and Rip Clark, but Clark was a fine fella, and he adored Ron."

Lyle had been making a comeback, and last March he scored a 12-round decision over Joe Bugner in Las Vegas. Clark was not there to watch the fight. There were press reports that Lyle had fired Clark just before the fight. Hayes has his own version.

"Ron didn't want Clark around him anymore because he (Clark) still liked Daniels and the others from the club (now disbanded)," Hayes said. "So one day he had Clark spar with him as a warmup for Foreman. He beat him up so badly that Clark wasn't able to make the trip. And after that, Lyle just ignored him."

Sam Boardman, now Lyles trainer, disputes Hayes story. He said that Lyle fired Clark early last September, a few days before Lyle fought Stan Ward in Las Vegas. "Rip was a friend of Ron's and when Ron asked me to give him some work I went along. I let Rip spar with Ron and run with him in the morning. But he was a bad dude, always hassling Ron and everyone else. I think he felt he could use Ron to his advantage and he started making trouble.'Boa'rdman said.