Kimimaro's going to kick Kyuubi Naruto's ass down to Chinatown. (Meet the parents)

If Naruto fought using his own power from the start, and maybe figure out Kimimaro's jutsu secrets, then use Kyuubi chakra, things might be better for him, but since he's using the Kyuubi chakra from the get-go, it's pretty obvious that he's not going to win.

If, by chance, he does win though, it'd be a really big waste of a cool character that just got introduced.