Mike Tyson says he hated Michael Jackson's guts for YEARS -- calling him a "cold motherf**ker" -- until he got to know the singer ... and that's when everything changed.
The boxing superstar opened up about his experience with MJ on T.I.'s "Expeditiously" podcast ... saying Jackson dissed him backstage at a concert in 1986.
Tyson says he had just become the heavyweight champion of the world -- and had become super famous -- but Jackson treated him as if he was a nobody. Tyson said MJ straight-up hurt his feelings.
"It broke my ego," Tyson said ... "It crushed me."
Tyson says he harbored some serious animosity toward MJ for years -- saying, "That cold motherf**ker. I hated his guts forever."
But, a while later, a mutual friend approached Tyson and said MJ wanted to hang out -- so he swallowed his pride and visited with the singer, hoping to squash the beef.
Not only did they bury the hatchet, Mike says he quickly learned Jackson was a cunning genius, and not a "f**king idiot."
"He wasn't no f**king stupid little feeble lookin' boy like Peter Pan. He's f**king sharp. He knew what f**kin' time it was. It blew my mind."
Tyson even says MJ was a "player" who was an expert in seduction -- and the King of Pop would offer up pointers on how to land beautiful women.
"I thought he was a f**king idiot until I met him that day," Tyson said ... "I learned to respect him. I knew he was a player."