Sasuke had to use Curse Seal level 2, and second stage Sharingan to defeat Naruto.
wrong,
sasuke's sharingan went to level 3 in battle and so sasuke could read naruto's movement.
but ofcourse if naruto went 2 tailed, he would've beaten sasuke because that way naruto would've had more chakra and would be way more powerfull than in 1 tailed state.
truly believe if naruto ,without the kyuubi or itachi's power, went in a duel with kakashi = one dead naruto
that's half true im afraid.. that's just because kakashi had a reason to take things serious and according to the rules.. it was because his dad suicided and got blamed by konoha for not finishing the mission which was the main priority..unlike naruto who had noone at the very beginning and was doing childish things to get the attention of the villagers to they would notice him instead of ignore him..
that's one frikking hell of a boost of kakashi and not to forget sasuke, compared with naruto.
actually not to mention that naruto is already strong without kyuubi, just he doesn't know that much jutsu + he was acting like a kid and didn't took anything serious @ start unlike kakashi..
naruto has already a GREAT amount of stamina AND chakra..
the stamina and chakra of the kyuubi just BOOOSTS him A LOT!
remember the training @ start after kakashi's fight against zabuza were naruto and sasuke where doing the tree climbing training, were sakura finished the first kakashi even stated that unlike sakura, naruto and sasuke has GREAT amount of stamina and chakra.. and there naruto didn't even could use kyuubi's powers..he unlocked it after he ''thought'' sasuke was dead against haku.
so basicly, naruto still could to the tajuu kage bunshin no jutsu because of the great amount stamina and chakra he possesses without the kyuubi.
so to keep it short, naruto > kakashi with stamina and chakra.
but with discipline/skills/experience: kakashi > naruto.