The top two teams in five of the six Pools will go head-to-head in the traditional, pre-Christmas Heineken Cup back-to-back battles in December.
There are seven unbeaten teams after two rounds and two of them are in Pool 5 - ASM Clermont Auvergne and reigning champions Leinster Rugby. The two teams met at Stade Chaban Delmas, Bordeaux, in last season's semi-final.
They also clashed in the Pool stages in the 2010/11 tournament, meeting in the same order in December as they will in two months time, at Stade Marcel Michelin and then the Aviva Stadium, and were rivals at the quarter-final stage in Dublin in the 2009/10 season.
Leinster lead the series of games between the two teams 5-1 dating back to 2002, but four of those triumphs have been by four points or less. No wonder they are such huge box office.
The last four games between the two teams have attracted 113,376 fans at an average of more than 28,000 per game. Expect to see Stade Marcel Michelin and the Aviva Stadium full to over-flowing in Rounds 3 and 4.
Leinster head coach Joe Schmidt used to work with Vern Cotter at Clermont and his former side were the last team to beat the reigning European champions in the Heineken Cup two seasons ago, 20-13 at Stade Marcel Michelin in Round 3!
Since then Leinster have been unbeaten in their last 17 Heineken Cup contests, the last 10 as straight wins. Something will have to give on Sunday 9 December in the final fixture of Round 3.
"Being second in the pool ahead of these back-to-back games is not our favourite position to be in, because we will go to France chasing them rather than being in control of the pool," admitted Schmidt.
"We have won two from two but I hope there is more to come from us. There has to be more because we can't keep surviving these skinny margins."
Pool 4 leaders Ulster Rugby will travel to Northampton Saints for the first of their head-to-head battles. The Irishmen will take a three point advantage with them as they try to go one better than last season when they were beaten in the Heineken Cup final by Leinster.
Saracens have a double date in December with two-times winners Munster Rugby in Pool 1, starting with a first visit to Thomond Park since 2000. That season Munster did the double in the Pool stages, winning both games by a single point.
Jonny Wilkinson's Toulon side will travel to the Salford City Stadium for the first time in Round 3 as the runaway leaders of Pool 6. Their two wins have given them a five point cushion at the top as they try to book their first home Heineken Cup quarter-final.
The other table-topping clash in December will be between four times winners Toulouse and the Ospreys in Pool 2. The action kicks-off at Stade Ernest Wallon on Saturday, 8 December.
The Leinster v Clermont Auvergne Rivalry
2002/03
P4 Montferrand 20 - 23 Leinster Rugby Marcel Michelin 10,000
P4 Leinster Rugby 12 - 9 Montferrand Donnybrook 7,500
2009/10
QF Leinster Rugby 29 -28 Clermont Auvergne RDS 20,000
2010/11
P2 Clermont Auvergne 20 - 13 Leinster Rugby Marcel Michelin 16,106
P2 Leinster Rugby 24 - 8 Clermont Auvergne Aviva Stadium 44,873
2011/12
SF Clermont Auvergne 15 - 19 Leinster Rugby Chaban Delmas 32,397
2012/13
P5 Clermont Auvergne v Leinster Rugby Marcel Michelin
P5 Leinster Rugby v Clermont Auvergne Aviva Stadium
