2D Rotation of a Sprite - Quaternion.FromToRotation Smooth

Hello! Im trying to rotate a 2D sprite towards another one. I`ve tried

transfrom.LookAt(target.transform.position)

transfrom.LookAt(target.transform.position,Vector.forward)

transfrom.LookAt(target.transform.position,Vector.up)

Quaternion.Slerp(transform.rotation,target.transform.rotation,Time.deltaTime * Speed);

Quaternion.Lerp(transform.rotation,target.transform.rotation,Time.deltaTime * Speed);

It rotates x or y axis.I want a sprite rotate only z axis and face towards another sprite.
Only line that work perfectly is

    transform.rotation = Quaternion.FromToRotation (transform.position, 
target.transform.position - transform.position);

How can i rotate sprite smooth with this fucntion,or are there any other ways to do this?

Fixed by using :

  transform.rotation = Quaternion.Lerp(transform.rotation,Quaternion.FromToRotation (transform.position, target.transform.position - transform.position),Time.deltaTime);