England are guaranteed a Heineken Cup semi-finalist this season after former tournament winners Leicester and Bath found themselves on a collision course.
Bath's 3-3 draw against Toulouse in monsoon conditions at the Recreation Ground meant they won Pool Five.
But they finished as fifth seeds - sending them to Leicester in April - following the lowest-scoring game since Heineken Cup rugby began in 1995.
The sides have already met in the Guinness Premiership and EDF Energy Cup this season, with Leicester claiming a dramatic injury-time victory when they last faced each other just three weeks ago.
Harlequins' first quarter-final appearance since 1998 will see them host Pool Two winners Leinster, while Heineken Cup holders Munster host the Ospreys and Toulouse visit top seeds Cardiff Blues.
The ties will be played over the weekend of April 10-12.
Significant pool stage casualties this season include Wasps, Sale Sharks, Perpignan and Gloucester.
Toulouse, runners-up in Bath's group, are the solitary French survivors, progressing as eighth seeds in a competition that saw fellow French clubs like Stade Francais, Biarritz and Clermont Auvergne fall inside the distance.
Bath head coach Steve Meehan said: "Leicester will bring out the best in Bath, and vice-versa.
"To reach the last eight in Europe represents a pretty good effort.
"Our target at the beginning of the season was to finish top of our group, and one of the sides in our group was Toulouse.
"We will have a few players back from injury for the Leicester game, and the squad will be better prepared. I am sure it will be a very competitive game.
"We have not played anywhere near the standard that we did against Toulouse out there in the first match last October, and if we can get back to that form, we will see how far we can go."
The Tigers will possibly consider switching the tie to Leicester City's Walkers Stadium, while Quins could contemplate a Twickenham move for their Leinster showdown.
Munster's Thomond Park home in Limerick though will prove a monumental test for the Ospreys.
The Irish giants have lost only once there in the tournament's history - Leicester beat them in 2007 - and Munster will start as firm favourites, despite Ospreys boasting a star-studded squad.
Toulouse, Heineken Cup winners in 1996, 2003 and 2005, face a repeat of last season's quarter-final clash against the Blues.
On that occasion, Toulouse strolled to a 41-17 victory on home soil, but the rematch looks a far tougher proposition, given Blues' current rich vein of form and the probable Millennium Stadium venue.
France though, will have its lowest quarter-final representation in Heineken Cup history, and for the first time there will be no quarter-final played in France.
English clubs, meanwhile, will be at home in all four quarter-finals of the second-tier European Challenge Cup.
Top seeds London Irish entertain Bourgoin, Northampton host Connacht, Saracens face an all-Premiership clash at home to Newcastle, while Worcester meet Brive at Sixways.
After missing out on England's 2015 RBS 6 Nations campaign through injury, centre Brad Barritt admits he is determined to make up for that disappointment in style with club side Saracens during the season run-in.