You can implement a module and call below function
function modulename_preprocess_page(&$variables) {
unset($variables['title']);
}
This will unset default title, but there are 2 problems:
1. This hook is not called by all the themes. So you cannot entirely rely on this.
2. Some themes check if ‘title’ exits before showing breadcrumb. So if you unset title then your breadcrumb will also disappear.
So finally I came up with this hack.
drupal_set_title( ‘ ‘ );
Note that there is space between single quotes. This removes default title
