Chuck Liddell Says He'll 'Knock Tito Ortiz's Head Off'

Chuck Liddell already has his fight strategy for his 3rd scrap with Tito Ortiz -- "I'm gonna knock his head off."

TMZ Sports broke the story ... the 48-year-old MMA legend is coming out of retirement to fight on a MMA card promoted by Oscar De La Hoya -- and can't wait to get back in the cage with his old rival.

"When it's all over with, it's gonna be 3-0," Liddell said ... bragging about the 2 wins he already racked up over Ortiz during their fights back in the mid-2000s.

"He's trying to convince himself he can beat me -- it ain't gonna happen," the Ice Man told us outside a launch party for Humbyl crptocurrency in West Hollywood Monday night.

Ortiz sees the fight going down in a different way ... just last week Tito says he plans to make a couple million dollars "kicking Chuck Liddell's ass."