2D Collisions not registering at all.

I have been trying to figure this out for hours and I swear it should work but it just refuses to.

I have two 2D objects on the same layer at the same z position, both of which have 2D colliders and one of which (player) has a 2d rigidbody while the other is ticked as a trigger, with the following script:

 void OnTriggerEnter2D(Collision2D col) {
     if (col.gameObject.tag == "Player")
     {
                  Print ("Collision!!!");
                  Destroy (col.gameObject);
     }
 }

However no matter which object I attach it to, where I put the function, what I try to change it to, nothing happens when they collide? The tag is definitely right and I have tried it without the if statement as well to see if it is working.

If anyone has any idea of what else it could be that would be amazing :)