"The Worst Compatibility…!!" (最悪の相性…!!, Saiaku no Aishō…!!) is chapter 37 of the original Naruto manga.
Naruto, angry that Lee only wants to fight Sasuke, tries to prove himself by attacking Lee. He is quickly defeated. Impressed by Lee's abilities, Sasuke agrees to fight him. When he is left unable to keep up with Lee's movements, Sasuke suspects it is some sort of ninjutsu or genjutsu and so activates his Sharingan. Because Lee is using taijutsu, the Sharingan does not help since Sasuke lacks the physical training to replicate Lee's attacks. Lee prepares to use his Front Lotus on Sasuke but is stopped by Ninkame.