D7 Views 3: Filter by relationship based on nid and uid
I ended up achieving the result that I wanted with hook_views_query_alter:

function site_views_query_alter (&amp; $view, &amp; $query)
{
  if ('block_3' == $view-&gt;current_display) {
    $account        = SiteUser::loadByID(arg(1), TRUE);
    $query-&gt;where[] = array(
      'conditions' =&gt; array(
        array(
          'field'    =&gt; 'node.nid',
          // Return just the IDs
          'value'    =&gt; SiteContest::getContestsPlayedBy($account, TRUE),
          'operator' =&gt; 'in',
        ),
      ),
      'args'       =&gt; array(),
      'type'       =&gt; 'AND',
    );
  }
}