How to play an animation at least once before changing

Hello guys! I've got an enemy with attack and running animations, and will only do these at a certain range. Problem is that when I go between two given ranges too fast, the animations immediately change, making it unrealistic. I've tried using animation.CrossFade but it doesn't work much, so any ideas on how to fix this? Oh, and here's my script:

 var Player : Transform;
 var MoveSpeed = 1;
 var MinDist = 2;
 var MinDist2 = 4;
 var Unseen = 15;
 
 function Update ()
 {
     transform.LookAt(Player);
     if(Vector3.Distance(transform.position, Player.position) <= MinDist)
     {
         Debug.Log("Attacking");
         if(!animation.IsPlaying("Attack"))
             animation.CrossFade("Attack");    
     }
     if(Vector3.Distance(transform.position, Player.position) <= MinDist2)
     {
         if(Vector3.Distance(transform.position, Player.position) >= MinDist)
         {
             Debug.Log("Attacking2");
             if(!animation.IsPlaying("Attack2"))
                 animation.CrossFade("Attack2");
         }
     }
     if(Vector3.Distance(transform.position, Player.position) >= MinDist2)
     {
         if(Vector3.Distance(transform.position, Player.position) <= Unseen)
         {
             Debug.Log("Not in attack range");
             transform.position += transform.forward * MoveSpeed * Time.deltaTime;
             if(!animation.IsPlaying("Running"))
                 animation.CrossFade("Running");
         }
     }
     if(Vector3.Distance(transform.position, Player.position) >= Unseen)
     {
         Debug.Log("Not within sight");
         if(!animation.IsPlaying("Idle"))
             animation.CrossFade("Idle");
     }
     
 }

That's it. If possible, I want to be able to play the "Attack" animation at least once before switching animations. Thank you very much in advance, and have a good day!