The only reason ANYONE needs to prove Naruto is stronger than Sasuke.
The manga is called Naruto. Not Sasuke...
Moving on.
Which is why Naruto lost to Sasuke at the end of part 1. /thread
We're all forgetting one important thing. Sasuke is much more experienced in to-the-death battles than Naruto is, as Naruto retains a no-kill policy (the movies aren't canon, so don't go there). Sasuke is willing to kill Naruto, Naruto is thus far saying he is not willing to kill Sasuke. Sasuke is smarter than Naruto both in terms of actual intelligence and in terms of battle tactics. Perfected Susannno presents a huge problem for Naruto, as does the Blaze Release and Amaterasu.
Let's remember some key events in the series:
-Naruto is doing training for nature manipulation. His type is wind. Fire is strong against wind, and Naruto sadly notes that this is his goal, to keep Sasuke's flame going. Remember the circle Yamato shows Naruto? Fire is strong against wind.
-Sasuke hasn't really used EMS that much and he's about to get some power-up from whatever is in this scroll
-The Sharingan can nerf the Nine tails pretty hardcore as we saw with Obito making it his summon, and even Kurama warned Sasuke not to kill Naruto. Why? Kurama thinks that Sasuke could possibly kill Naruto. Kurama knows the power of Sharingan. We see Sasuke suppress Kurama inside Naruto's mind at the start of part 2.
-Sasuke is a lot smarter in battle than Naruto and is willing to kill Naruto, whereas the same is not true. That is a huge advantage even if your opponent is stronger.
Sasuke and Naruto will fight on equal terms. Expecting anything less is ridiculous fanboyism. It's the final battle, if it were a wash in one character's favor it wouldn't be dramatic. Whether Naruto will win or Sasuke will win isn't really relevant. Kishi might not even let us see that. It's unlikely they will really fight to the death anyways.
Making a thread and saying "HURR Naruto > Sasuke becuz the series is called Naruto!!11oneone" is pointless. Naruto has lost plenty of fights and so has Sasuke. The title character doesn't win every fight he's in.