First post bigger than the rest

Hi,
I’m trying to make the first post bigger than the rest of them. Since the settings of the loop widget work for all the posts, I put a first loop widget above, with the content_single.php template. Everything works fine, except that the first (I mean, the most recent) post is repeated in the loop below. I there a way to tell the loop widget to display all posts except the last (recent) one?
Thank you for your attention.