The Third Kazekage (episode)

Synopsis
Sasori attacks with an Iron Sand pyramid and prism, but Sakura is able to fend them off, causing a cave-in in the lair. Sasori then uses the Iron Sand to create a makeshift globe-model out of randomly growing spikes of iron, one of which hits Sakura and paralyses her with poison. With a one last attack from the Third Kazekage puppet, Sasori attempts to kill the seemingly helpless Sakura, only to discover that Sakura is somehow immune to his poison and she destroys the Third Kazekage puppet with a single punch.

Trivia

 * During Sakura's flashback to her training with Tsunade, an animation error occurs, which shows Sakura before she took part in the Chūnin Exams again. This is impossible, because Sakura had already cut her hair short when Tsunade arrived and was much taller as well.