Pokémon S02E36 - The Rivalry Revival

Ash and Gary have a battle, and although he puts up a fight, Ash ultimately loses. Later, Professor Oak is examining the GS Ball and can not find out anything about it. Ash comes in and Oak tells him that Gary has left on his next journey, the Johto region. Ash becomes upset knowing that Gary is still ahead of him, and he decides to head to Johto as well, and he may have a few surprises before heading out.