You have trained hard as an aspirant, <name>, and now the time has come to test your mounted combat skills against a skilled opponent.
Equip a lance from the lance rack at the stables on the southern side of the tournament grounds, then mount up on the Quel'dorei steed.
At the Aspirant's Ring on the northern side of the tournament grounds, you'll find Squire David. He'll make certain that you're ready for the fight and call out your opponent.
Good luck, <name>. May your horse be steady and your aim true.
Rewards
Progress
Have you faced your challenge?
Completion
Congratulations are in order, <name>. You have bested the challenger and earned the right to advance to the rank of valiant.
Notes
Pick up the steed in the same location as for the mounted daily quest, then run to the opposite side of the keep to the north, just north of the profession trainers. Talk to the Squire, let the summoned combatant come to you, then run away and start the fight. It's fairly easy.
If you fail, you will be knocked of your horse. Mount a new one (there is one nearby) and talk to the Squire again to re-try the test.
After completing "The Valiant's Challenge", the following quests open up allowing players to repeat the valiant stage of daily quests (steps six and seven) for the other factions with which they have not yet earned the right to champion: