The solution depends on what is causing the last page to remain (eg extraneous para mark, page break or section break).
If it's just a matter of an extraneous para mark or page break, you'll have to delete that too. Likewise if it's a section break, but in this case you'll need to be careful about the implications for page attributes (eg dimensions, headers & footers), since deleting a section break causes the previous section to inherent the attaributes of the deleted section.
Cheers