i think he either
1)rapped so much the kyuubi agreed to let him use its power if he would just shut up
2)since bee had 2 "suns" his will was not breakable.
3)bee is awesome
Didn't KB have to beat him in his subconscious to tame the eight tails? o.o
So to a extent yes he did but all I'm guessing he had to do was take away his chakra to a different place like naruto but not as powerful as his. But in a real fight I'd assume that the eight tails would win. But I'm not sure how he could of defeated the eight tails in that battle, we've only seen him use his special tai and a couple lightning techniques. :\
How did Naruto win against Kyubbi? Go ahead, think.
He kept charging chakra in his transformed SM, in his stationary Stance.
So, maybe Kirabi has an "unlocked" form that he used to use before he controlled Hachibi.
That he constantly had chakra to charge for.