(Kamui restriction is a given)
And I do agree that Kakashi wins this match, but really? Low difficulty?
come on guys Darui aint Sakura, Ino or some other fotter ninja, the match won't be won with low difficulty, heck i even don't think it will be won with mid difficulty (but im not saying it will be high eighter, somewhere in betwean of mid and high) it will take time to take Darui down, and alot of Kakashi's chakra aswell... Don't forget the fact that because Kakashi is not a Uchiha so even using the sharingan normally drains more than just a minimal ammount of chakra, every single match Kakashi used the Sharingan in he had to be hospitilized after...
Kakashi is not a pure blood Uchiha like Sasuke or Itachi who could keep the sharingan active all day without any problems, and Kakashi's usual tactic with stay hidden and fight with a lightning clone that will burst in to small field of electricity that will temporalily paralyse his opponent won't work on Darui sins he also have the lightning afliction.