Why is it impossible to knock out AI in this game?!?!?

Why is it literally impossible to knock out AI? So i had a match in career mode and I hit my enemy 128 times in the head in 1 match, his head was literally f*cked up, but he still knocked me out with 1 punch to my head. What are their heads made of, as it seems to be impossible to knock em' out... I tried the same match 12 more times, but the result was the same every time. I hit the enemy like 100+ times in the head, his head was red and i hadn't taken almost any damage, then he hit me in head and i was knocked out and lost. #logic