@Fehafare: He may have been beaten fast/strong opponents. But notice how he used the fox in nearly every fight and would have died without the speed/power boosts. Hell he wouldn't have made it past the first arc. The only time where his speed was formidable was when he was using Mr. Kurama. His tree jumping/running speed doesn't really come into play when fighting a pretty much stationary opponent.
Like I said before, it doesn't make any sense to assume that he wouldn't get hurt by spells, especially the bleeding spell. Naruto is cut just as easily as any human. And the torture curse simply makes you feel pain. Even if its to a lesser degree, Naruto should feel it.
So in conclusion, the only way Harry could win is catching Naruto by surprise immediately. If he misses his 1 shot, Harry gets the Naruto Barrage and dies. So Naruto like 9.5/10 on the off chance that Naruto is spacing out.