Redirect to post when search query returns single result

Put this snippet into the functions.php file of your WordPress theme to redirect your search to the post automatically when WordPress only returns a single search result.

add_action('template_redirect', 'single_result');
function single_result() {
    if (is_search()) {
        global $wp_query;
        if ($wp_query->post_count == 1) {
            wp_redirect( get_permalink( $wp_query->posts['0']->ID ) );
        }
    }
}