Paris - Reigning champion Toulon have been handed a home tie against Glasgow in the opening match of their European Cup defence following Monday's group phase draw.
Toulon will begin their Group 2 quest at their Stade Mayol home on October 13 before travelling to Cardiff six days later than then heading to Devon to face Exeter on December 3.
Last season's runners-up Clermont begin their Group 4 challenge on October 13 with a mouth-watering domestic clash against big-spending Racing Metro.
Perhaps the plum tie of the opening weekend comes on Friday October 11 when English champions Leicester travel to fellow former European Cup winners Ulster in Group 5.
Another clash of the titans to look out for is on Friday October 18 when Saracens tackle record four-time European champions Toulouse at Wembley in Group 3.
First round of fixtures (all times GMT):
Friday October 11:
Connacht (IRL) v Saracens (ENG) (19:00), Toulouse (FRA) v Zebre (ITA) (19:00)
Ulster (IRL) v Leicester (ENG) (19:00)
Saturday October 12:
Castres (FRA) v Northampton (ENG) (14:40), Ospreys (WAL) v Leinster (IRL) (16:00)
Harlequins (ENG) v Scarlets (WAL) (14:40)
Treviso (ITA) v Montpellier (FRA) (12:35)
Edinburg (SCO) v Munster (IRL) (12:35), Gloucester (ENG) v Perpignan (FRA) (17:00)
Sunday October 13:
Exeter (ENG) v Cardiff (WAL) (1145), Toulon (FRA) v Glasgow (SCO) (14:00)
Racing Metro (FRA) v Clermont (FRA) (19:00)