Goh catches a Dewgong.
This marks the longest time taken for Ash to catch his first Pokémon in a new series, at ten episodes, surpassing Pokémon the Series: Ruby and Sapphire and Pokémon the Series: Sun & Moon, both in which he caught his first Pokémon four episodes in.
This marks the first time Ash has non-temporarily caught a fully-evolved Pokémon since he caught Noctowl in A Differently Colored Yorunozuku! Catch It!! (2000), 941 episodes earlier.
Ash catches a newly evolved Dragonite.