Rotation of object placed in the middle point between two points?

Hello everyone,

My situation is that I want to rotate an object by changing the position of two points. This points are at the ends of a segment which's middle point is my object.

This is the code and it's working around the z axis, but when I try the same on the y axis it doesn't work; I need the rotation on both z and y axis at the same time.

 Vector3 direction = p2.transform.position - p1.transform.position;
 object.transform.rotation = Quaternion.FromToRotation( new Vector2(object.transform.position.x, object.transform.position.y) , new Vector2(direction.x, direction.y) );