Shortcode header appears before content

I’m trying to create shortcode, that should display random post.

function zalgiris_random_post() {
	global $post;
	$args = array( 'orderby' => 'rand');
	$myPosts = get_posts($args);
	$result = '<h2>Random post: </h2>';
	$post = $myPosts[0];
	$result .= the_title();
	return $result;
}

The problem is, that the title of the post actually appears before Random post header. Why that happens?

I’m also new, I found that if I remove global post from the top of the function, it doesn’t work. What global post is so special? Is it used to reference for a single post?