Twice champions Leicester were knocked out of the Heineken Cup after a controversial 17-12 Pool Three home defeat by the Ospreys with the Welsh side progressing as one of the best runners-up.
The exit of Leicester, last season's runners-up, means there will be only one English Premiership side in the quarter-finals -- Northampton or London Irish -- in English rugby's worst performance in Europe's elite club competition.
Clermont Auvergne went through as Pool Three winners when they thrashed Viadana 59-20 in Italy to secure top spot thanks to their bonus point win.
Stade Francais stumbled across the line to top Pool Four as their 9-7 defeat at Edinburgh gave them a bonus point that was enough to progress despite Ulster's impressive 28-10 victory at Bath.
Holders Leinster, already certain to go through either as winners or runners up in Pool Six, play London Irish at Twickenham.
London Irish need to win with a bonus point to guarantee their progress while a non-bonus point win with a try would also be enough to pip Northampton for the remaining best runners-up slot.
In earlier action Munster beat Northampton 12-9 to top Pool One and reach the quarter-finals for the 12th year in a row.
Three times champions Toulouse were already through from Pool Five as were Biarritz from Pool Two.
Both French sides complete their Pool campaigns this weekend.
The six Pool winners and two best runners-up qualify for the quarter-finals.
