Mike Tyson weighed in at his lightest for 23 years for his exhibition bout against Roy Jones Jr on Saturday night.
Jones scaled 210lb - the heaviest of his career - before Tyson weighed 220lb, the lightest he has been since he took a chunk out of Evander Holyfield's ear in their 1997 rematch.
Jones' previous heaviest was 204lb for his clash with Eric Watkins in 2015 having moved through the weights from middleweight to heavyweight as a professional.
After weighing in, he said cryptically: "I can't tell you how to do it, it's probably going to look wrong. If I try to tell you it's probably going to sound wrong. But it's going to turn out right, trust me."
And Tyson added: "I'm pitching punches and anything else is up to Roy.
"If I am running anywhere, I am running right at him."
The fight, which will take place over eight two-minute rounds, has been shrouded in controversy this week over whether the legends can knock each other out.
The California State Athletic Commission, who have sanctioned the bout, insist not but Tyson and Jones disagree.
A winner will be announced by the WBC who will have three former champions scoring the bout remotely.
And Tyson added: "As soon as I hit him good... I don't know, maybe I don't know how to go easy.