Jack Swagger and CM Punk are former WWE World Heavyweight Champions turned MMA fighters ... but that's where the similarities end, 'cause Swagger tells TMZ Sports when he fights, he ain't losing.
Big facts ... Swagger -- real name Jake Hager -- was a pro wrestling superstar. But, he was also a stud on the wrestling mats in college -- earning All-American honors at Oklahoma in '06.
That's precisely why 6'7", 265 lb Swagger says when he steps into the cage to fight J.W. Kiser at Bellator 214 on January 26 ... he'll look NOTHING like Punk -- who got destroyed in both of his UFC fights.
"I'm different for so many reasons," Swagger told us ... "I've been wrestling since I was 5 years old, bro."
"I have over 150 Division 1 college wrestling matches, and I'm gonna rely on that as my amateur MMA and boxing career to help when the anxiety kicks in."
Punk -- who lasted less than 3 minutes before Mickey Gall almost choked the life outta him -- had no prior combat experience before signing with the UFC at 36-years-old ... no real wrestling, boxing or jiu-jitsu experience to lean on.
"I think the biggest thing that you're gonna see is the difference between me and him is that I am prepared. I am 100% prepared to take this fight, to go into that Octagon, go in that cage and inflict my will on anybody."