About Game Spectating

If I understand you right you're asking for a way to spectate a championship game through the game client and not through something like Twitch.tv?

Unfortunately this isn't possible as (at leas as I am to understand it) championships and major tournies are usually hosted locally or on a private Riot server that does not allow direct access by anything other than the spectator client available to the shoutcaster, which is then shown through streaming services.