Mike Tyson and Roy Jones Jr are now not allowed to knock each other out when they share a ring for an exhibition bout on Saturday night, according to UFC president Dana White.
The boxing legends, Tyson is 54 and Jones Jr 51, are stepping back into the ring but under a very different rule-set.
There will be no ringside judges; therefore, no winner will be announced for the bout, which will be eight rounds of two minutes each.
Tyson and Jones Jr do not have to wear protective headgear but will wear 12oz gloves, bigger than the usual gloves worn in elite boxing.
If either man is cut, the bout is immediately over.
They each had to sign up to Voluntary Anti-Doping Agency testing beforehand.
UFC president Dana White’s gave a baffled reaction to the rules set up by the California commission: “There’s no knockouts? They’re not allowed to knock each other out?
“How do you enforce that?”
Jones Jr told reporters earlier this year: “If it comes down to bite, we’re going to bite. Whatever has to happen, is going to happen, that’s just what it is.
“He’s still Mike Tyson, he’s still one of the strongest, most explosive people who ever touched a boxing ring. If anything, I made a mistake going in with him. He’s the bigger guy, he’s the explosive guy.
“He’s going to have all the first-round fireworks, not me. I do have first-round fireworks, but he’s known for more first-round fireworks than anybody to ever touch boxing, other than maybe George Foreman.
“With him having the first-round fireworks, he’ll be against a guy smaller than him, maybe 40-50 pounds smaller than him.”