Three clubs, ASM Clermont Auvergne, Harlequins and Toulon, have five wins with one round to go and are on track to join the group of eight clubs who have achieved six wins from six in a Heineken Cup pool stage.
However, no club which was won all six games in the pool stage has ever gone to lift the Heineken Cup in that season.
London Wasps 1997/98 - lost in quarter-final
Bath Rugby 2001/02 - lost in quarter-final
Leinster Rugby 2002/03 - lost in semi-final
Leinster Rugby 2004/05 - lost in quarter-final
Scarlets 2006/07 - lost in semi-final
Biarritz Olympique 2006/07 - lost in quarter-final
Cardiff Blues 2008/09 - lost in semi-final
Northampton Saints 2010/11 - lost in final
Munster Rugby 2011/12 - lost in quarter-final