Well, in such a fanfiction, perhaps Sasuke has some sort of plan that involves Hinata in a negative way. Naruto discovers this and decides to beat up Sasuke to protect Hinata. It could also be part of a bigger struggle where Sasuke's actions are seen as a threat to the future Naruto envisions with Hinata, so Naruto takes matters into his own hands to stop him.
Hinata might be shocked at first. She is a gentle soul, so seeing Naruto be so violent towards Sasuke would be unexpected. But then she would probably try to stop Naruto, as she doesn't like to see people fighting. She might also feel a bit guilty, thinking that her relationship with Naruto somehow caused this conflict between the two friends.
In fanfictions about Naruto beating Sasuke in the Chunin Exams, the story could take a different turn for their relationship. Usually, Sasuke is the more skilled one in the early parts. But if Naruto wins, it could lead to Sasuke being more envious and determined to surpass Naruto in a different way. Naruto, feeling proud of his victory, might also be more motivated to keep getting stronger to maintain his edge over Sasuke.
One common theme is the power of friendship. Naruto often uses the bonds he has formed with his friends as a source of strength to defeat Sasuke. Another theme is self - improvement. Naruto typically has to grow and develop new skills to be able to overcome Sasuke.
One possible reason could be to protect Hinata. Maybe Sasuke has unknowingly made a move or decision that Naruto perceives as a threat to Hinata, so he scares Sasuke to make him back off.
In NaruHina fanfictions, Naruto might ignore Sasuke because he finally finds true love and stability with Hinata. His focus shifts from the turbulent relationship with Sasuke to building a future with Hinata.
One possibility is that Naruto's win would cause a stir in the ninja academy. His peers would start to study his techniques more closely. Kakashi might also take a different approach in training them. As for Sasuke, he could become more withdrawn, focusing all his energy on getting revenge on Naruto for this defeat. This would add a new layer of conflict to their relationship and the overall story.
One popular 'naruto beats sasuke fanfiction' is 'The Victor's Path'. In this fic, Naruto overcomes Sasuke through his unwavering belief in friendship and the power of the village. It shows Naruto using new jutsu he developed through intense training, which gives him an edge over Sasuke's power-hungry techniques.
Hinata might be initially worried. She doesn't want any conflict between Naruto and Sasuke because she cares about both of them. But at the same time, she could feel a bit flattered that Naruto is so protective of her.
One common theme is Naruto's growth. He often overcomes Sasuke because he has developed as a person and a ninja more than Sasuke. For example, in many fics, Naruto has a stronger sense of purpose and friendship which gives him an advantage.