Defending champions Leinster face the daunting task of travelling to Clermont for Sunday's first of two Heineken Cup encounters between the duo.
The Irish province and French giants are both unbeaten in Pool Five, but Clermont have a two-point advantage thanks to two crucial bonus-points garnered from games against the Scarlets and Exeter.
It must also be remembered that Clermont are unbeaten at their Parc des Sports Marcel Michelin venue in more than three years, a record which they will defend with great pride.
The matches throw up the chance for Leinster's Kiwi coach Joe Schmidt to return to Clermont - where he worked under compatriot Vern Cotter before relocating to Ireland - and he is now being touted as a likely candidate for the coaching team for the British and Irish Lions to Australia next June.
"Qualifing from the pool will depend on this double header," said Cotter.
"They, as we have done, have long marked this date in the calendar.
"My players are very excited, focused and motivated by the idea of playing this match."
Cotter said Leinster, who beat Clermont 19-15 in last season's semi-final, were not a team to be underestimated.
"They're a team which controls the ball well and plays with a lot of speed," he added.
"They're used to big matches and this competition.
"With a two-point deficit on us, they know that they don't have any other solution than to go away with a result here.
"I know Joe well and I'm sure he'll try to move the ball around. We'll have to be ready to adapt by remaining focused and accurate."
Leinster prop Cian Healy knows that beating Clermont in their own backyard will not be easy but he believes they can achieve that goal.
"We're pretty focussed on Clermont and what we have to do there," he said.
"It's a big two games and what we have to bring to that away game is going to be a big ask.
"We expect the exact same again. Their physicality is a big thing they bring and their defence is hard."