[development] hook_menu vs path alias Drupal 7

[Deva]

Hi All,

I am developing a site in Drupal 7. I have a node with alias /article/hello
I also have a hook_menu with "/article/hello" path registered in my module.
When i access the path in browser http://localhost/article/hello it shows
the node instead of calling "my_custom_function".

$items['article/hello'] = array(
    'title' => 'Hello World',
    'description' => 'Hello world',
    'page callback' => 'my_custom_function',
    'access arguments' => array('access content'),
    'type' => MENU_CALLBACK,
);

I want 'my_custom_function' to get called.
Appreciate your help.

-- 
:DJ