He got jabbed on the side of the chin causing the nerve behind the jaw to compress. It was a tiny hit, but in the perfect spot while he was lunging forward. Anyone can get rocked like this.
Kimbo really shouldnt have taken the fight. He had nothing to gain by fighting Seth. Plus Shamrock woulda looked like the tool-of-the-night for getting cut backstage. Now Kimbo has that title.
BTW did you hear the mad shit Frank was talkin about Ken at the beginning?!? "He's disgracing the Shamrock name and legacy..." HAHAHA