Taking on a foe more powerful than you only increases the fury of your attack.

Encounter   ✦     Primal, Weapon
Standard Action      Melee weapon

Target: One creature

Attack: Strength vs. AC. If the target's current hit point total is higher than yours, you can score a critical hit on a roll of 19–20.

Hit: 2[W] + Strength modifier damage. If this damage makes the target's current hit point total lower than yours, you also knock the target prone.

Published in Primal Power, page(s) 113.