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In the *Naruto* series, Rock Lee does not open any of the Eight Gates during his fight against Sasuke Uchiha during their first encounter at the Chunin Exams in the anime and manga. During that fight, Lee demonstrates his natural speed, agility, and taijutsu skills, overwhelming Sasuke without using the Eight Gates.
The Eight Gates are a forbidden technique that Lee uses sparingly, primarily in dire situations, such as during his fight against Gaara or later against more powerful opponents. Against Sasuke, his base abilities were more than enough to make an impression and highlight the gap in their taijutsu skills at the time.