Meanwhile, France are guaranteed to stage a semi-final after it emerged that the winners of the ASM Clermont Auvergne v Montpellier quarter-final will also have home country advantage when they take on the victors of the much-anticipated clash of this season's number one seeds, Harlequins, and two-time former champions, Munster Rugby.
HEINEKEN CUP SEMI-FINALS
(To be played 26 / 27 / 28 April)
The winner of the first named quarter-final in each semi-final pairing will have home country advantage.
Semi-final 1: Saracens or Ulster Rugby v Toulon or Leicester Tigers
Semi-final 2: ASM Clermont Auvergne or Montpellier v Harlequins or Munster Rugby