Here's why:
* Their fight ends in a stalemate: In chapter 136, their fight ends when Sasuke uses his curse mark to overpower Naruto and escape with Orochimaru.
* Orochimaru flees: Orochimaru is never defeated directly by Naruto in the manga. He simply retreats after realizing that Sasuke is more useful to him.
It's important to note:
* Naruto vs. Orochimaru in the anime: The anime adds a scene where Naruto and Orochimaru fight again, but that scene is not canon.
* Sasuke vs. Orochimaru: Sasuke, Naruto's rival, eventually defeats Orochimaru in a very dramatic battle.
So, while Naruto and Orochimaru have a fierce clash, Naruto doesn't manage to get a definitive victory over him in the manga.