Speak with Justicar Mariel Trueheart at the Argent Tournament Grounds.
You have earned my respect and the respect of your peers. You defeated all who challenged you and mastered the ways of tournament combat. I have no doubt that you are ready to face down the champions of other cities for the glory of the Thunder Bluff!
Justicar Mariel Trueheart has asked to speak with you, <name>, and to formally enter you in the champions' grand melee.