Kyle may not have been Hogan's size, but he's still a decent sized guy. I'm sure he's in good shape too. Also, knocking someone out isn't about pure size and strength - it's about where you hit a guy, and the effect is magnified if he doesn't see the shot coming. Kyle admits to sucker-punching him, so Hogan could have been dropped and shaken enough to allow Kyle to run, as he stated he did.
"The best kind of pride is that which compels a man to do his best when no one is watching."