Gaara vs. Rock Lee: The Power of Youth Explodes!

is episode 48 of the original Naruto anime.

Synopsis
After a long wait, Rock Lee was set to fight against Gaara. At first it seemed as though Lee's Strong Fist taijutsu would be ineffective because of Gaara's Shield of Sand, a wall of sand that automatically rises to protect Gaara regardless of his will. Lee soon revealed that he was wearing heavy leg weights and removed them, allowing him to move faster than before and to ultimately bypass Gaara's sand. Lee attempted his Front Lotus.