keep in mind that they both require close quarter combat to be fully effective.
which means that the gentle fist would win this.
even if kakashi uses his ninja dogs to try and disable hiashi, he'd just rotate using 64 palms trigram or w/e that was to block the dogs.
not only that, he can see them coming due to his byakugan.
kakashi can predict and evade hiashi's movements but eventually someone has to give and as i recall, the reason to why kakashi blocks off his sharingan is so that he won't use up his chakra.
on the long run, the experienced and natural byakugan user would win over the highly skilled, un natural sharingan user.
the skill set alone says it all.
hiashi can block long ranged attacks and disables close quarter ninjutsu and targets vital spots.
kakashi requires close quarter combat with chidori/raikiri for a limited amount whilst hiashi can still spam.
hiashi wins.
with kamui Kakashi wins 
