Animation Doesn't Play on Pivot Point

Here's the problem.

I have a door knob which has a pivot point in the center of mesh and when it rotates, it rotates like door knob is spinning in its center.

I created an empty game object to create a pivot point and on Animation window I created opening and closing animations, and they play just fine on Animation window play, just around the pivot point and it looks exactly as a door knob would rotate around its pivot point.

However when I play in game, animation plays but not around pivot point, around mesh center.

How can I fix this?