The two side’s European fortunes could not have been more contrasting this season, as Harlequins were rampant in their group, while the Irish side scraped into the quarter-finals as the second-best runner-up.
The fixture, due to be played 5-7 April, is a highlight as Munster’s European credentials will severely test the entertaining London side.
The winner will have to travel to France to face the winner of Clermont and Montpellier after the semi-final draw was announced on Sunday evening.
After a bonus-point victory at the weekend, Saracens were rewarded with a home tie against Ulster. The Irish side have been imperious domestically this season but have stalled slightly in Europe.
Sarries, who seem to have found a cutting edge in this competition, will fancy their chances at their new stadium, Allianz Park, in April.
Leicester, who triumphed in their must-win match against Toulouse in snowy conditions, face a daunting trip to the French “Galaticos” Toulon, in what is guaranteed to be a thriller.
It is a clash of mentality as the Tigers pride themselves on their team unity and collective might, while the French side can draw on pure inspiration and individual brilliance from any one of their superstars.
If both English sides get through then they will face each other in a semi-final to be played on 26-28 April.
Harlequins v Munster
Clermont Auvergne v Montpellier
Toulon v Leicester
Saracens v Ulster
(Ties to be played on the weekend of 5-7 April)
Saracens or Ulster v Toulon or Leicester
Clermont Auvergne or Montpellier v Harlequins or Munster
(Ties to be played on the weekend of 26-28 April)