ActionScript 3.0 :: Calling A Function From An Extended Class Inside A Top Level Class

package{
public class Character{
protected var _hp:uint = 50; //Character Health Points
protected var _power:uint = 5; //Damage dealt

[Code].....

I`m instancing a Character and a Player in the Main Timeline, all in frame 1.
When I use: ""player.attack(character)"" it works fine by itself.

So I added the if (defender._hp <= 0) this.win() which gives me the following error:

1061: Call to a possibly undefined method win through a reference with static type Character.

"defender" is a Character instance, "this" is a Player instance and "win()" is a Player method. I try to call the Player method inside a Character method using the Player instance adding the "." and his method name

Do I really need to define the win() function in the Character class? Is there a bypass to use a subclass method in a parent class method if it`s called from an instance of the subclass?