Which Pokémon game was the first to feature official online battles and trading through Nintendo Wi-Fi Connection?

Pokémon Diamond and Pearl were the first main-series games to feature official online battles and trading through Nintendo Wi-Fi Connection. The Nintendo DS pair launched in Japan in 2006 and used the system's wireless service to connect players globally.

Earlier Pokémon games supported local link-cable or infrared exchanges, but Diamond and Pearl added internet matchmaking through facilities such as the Global Trade Station. Players could deposit, search for and request Pokémon from other users, transforming trading beyond nearby friends.

Nintendo Wi-Fi Connection was discontinued in 2014, so the original online functions no longer operate through Nintendo's official servers. The games remain historically important because they introduced the first official internet infrastructure for core Pokémon battles and trades, while later titles moved to newer online services.