Happens a lot in K1, and that big lump also got KO'd a couple of times by very small heavies. And of course it does happen in boxing as well. Heavyweight is Heavyweight, doesn't matter if you're 5' 9" or 7' 1". That's what makes it such an intriguing weightclass. Valuev (7' 1") beat Dominguez (5' 9½") in 2004 over 8.
Youve got a point there bro, but i think the thai guy was nowhere near the weightclass of that big korean lump. Did some research though and found out that the guy got KOd by smaller heavies indeed as seen on this vid. The danish guy beat the sh*t out of the korean http://m.youtube.com/watch?v=U5G-Du_LbOM For a 5"11 guy, iron mike beat a lot of guys way bigger than him as well..
But in the 80s Tyson still outweighed all his taller opponents Tony Tucker Josie Ribaltia and Mitch Green all were 6 foot 5 or over but Tyson still had the weight on his compact frame.
The smaller Thai fighter was only 85kg/187lbs so he'd be a small cruiserweight, compared to Kim Young Hyum the Korean who was 142kg/313lbs, massive weight difference.
Yup. I was just about to post that and besides being a tiny HW, Pettas was semi-retired. The big Korean dude came out of their version of Sumo, much like another giant Hong-man Choi who had more success but also got knocked out cold by a D level boxer Mighty Mo.