Aslan the Lion vs. Cave Troll
Aslan is a talking lion, King of the Beasts, son of the Emperor-Over-the-Sea; a wise, compassionate, magical authority (both temporal and spiritual); mysterious and beloved guide to the human children who visit; guardian and savior of Narnia. The author, C. S. Lewis, described Aslan as an alternate version of Christ—that is, as the form that Christ might have appeared in a fantasy world. He is also a big f*cking lion who knows how to fight.
The Cave Troll from LOTR: TFOTR is a large, fast, powerful, and wild troll with natural armor-like hide due to it's hide being arrow-proof and very resilient to swords and stabbing weapons (not that it couldn't be stabbed). The troll from TFOTR was killed by Legolas only because of an arrow being shot into it's mouth and going through the soft palate of it's mouth into the brain.
Two mythical beasts.
Fight takes place at the big ass grassy field where the first Narnia movie has it's final battle.
No weapons. Hand to............, well, uh, claw and teeth.