<xsl:variable name="rows" as="element(xhtml:tr)+">
   <xsl:for-each-group select="/results/match" group-by="team">
     <xsl:copy-of
  select="my:MakeTableRow(current-grouping- key(),current-group())"/>
   </xsl:for-each-group>
 </xsl:variable>
 <xsl:for-each select="$rows">
    <xsl:sort select="xhtml:td[8]"/>
    <xsl:copy-of select="."/>
 </xsl:for-each>

Thanks again
Leo