I don't think those two would ever fight and if they did, of course kyuubi would win, i mean if he can't be defeated and has to be sealed away then naruto won't beat him, plus naruto is naruto because he has kyuubi's chakra, if kyuubi was out so that they could fight then i would assume that naruto dosn't have kyuubi's chakra.. and i'm going to have to agree with aeon about if naruto beat kyuubi would be time to stop watching because that would make little sence