Killing a dragon with a single Dragonrend shout

the-elder-scrolls-v-skyrim

My character is level 19 and I came across a dragon and went about to kill it the usual way (Dragonrend, Sword hacking).

Only this time, the dragon just died when I used Dragonrend. Is this possible? Are there weak dragons to look out for in Skyrim for some quick dragon souls?

EDIT: This is after I have:

already killed Alduin and Paarthurnax.

Best Answer

Dragonrend apparently does an unspecified amount of health damage over time to dragons. Are you sure the dragon was at full health when you shouted at it? They are surprisingly frail creatures, when matched against groups of bandits or a giant.