<page_title> List of World Championships records in swimming </page_title> <section_title> Men </section_title> <table> <cell> 100m backstroke <col_header> Event </col_header> </cell> <cell> r <col_header>  </col_header> </cell> <cell> Aaron Peirsol <col_header> Name </col_header> </cell> </table>
In his first event, the 100-meter backstroke, Peirsol won a championship.