Identify Yourself: Powerful New Rivals

is episode 21 of the original Naruto anime.

Synopsis
As the Sand Siblings are introduced, Gaara scolds Kankurō for his abuse of the kids. Gaara then apologises to Sasuke for Kankurō's behaviour. The three are ninja from the sand village, they are in Konoha for the Chūnin Exams. The Third Hokage asks Kakashi, Asuma and Kurenai to step forward and recommend any Genin they believe to be fit to take the Chūnin Exams. Iruka thinks that the rookies need more time, and that there is no way that any of them will be recommended. However, all three jōnin recommend their students which shocks Iruka greatly. Iruka challenges their decision, as he believes Naruto and the others are not ready for the exam. They however stand by their decision and the Hokage agrees, but only after Kakashi reminds Iruka they are no longer his students, but ninja under his command. The next morning Kakashi gives Team 7 the application forms for the Chūnin Exams. Both Sasuke and Naruto accept, but Sakura is uncertain. Later, all three of Team 7 are attacked by a mysterious ninja from a different village. Moegi is captured, and Naruto saves her, but the mysterious ninja escapes. Sakura is taken in by his genjutsu but quickly figures it out. Despite this she is still uncertain about the exam. Sasuke easily defeats the ninja, telling him to stay out of Konohagakure. The ninja is revealed to be Iruka in disguise. He reports back to Kakashi, confirming they all passed his test. Inside the school registration for the exam is taking place, but two shinobi bar the way warning all the genin about the exam. An altercation nearly takes place but Rock Lee steps in and diffuses the situation, which surprises Sasuke. Rock Lee later goes after Sasuke and challenges him to a duel.

Trivia

 * Iruka testing the members of Team 7 is unique to the anime.