There were 41,063 fans at Wembley Stadium watching Saracens beat the Ospreys 31-26 in Round 3 - the fifth highest Pool match attendance in the 17 seasons of the tournament - and advance sales for the Aviva showdown are already around the 43,000 mark.
Leinster moved three points clear of Glasgow Warriors at the top of the Pool after both notched up wins, Glasgow beating Montpellier 20-15 while Heineken Man-of-the-Match Jonny Sexton accounted for all Leinster's points with six penalty goals in the 18-13 win over Bath.
"We have a good win ratio at the Aviva - we have not lost there in the Heineken Cup - and it is great to be playing at the home of Irish rugby," said prop Mike Ross.
"The win in Bath means things are in our own hands so it is up to us to get another win on Saturday to keep accumulating points and so, hopefully, keep us in the mix for a home quarter-final."
Leinster are now unbeaten in their last nine Heineken Cup games, the only blemish the 16-16 Round 1 draw at Montpellier. That run includes three contests at the Aviva - a 24-8 Pool stage win over ASM Clermont Auvergne; a 17-10 quarter-final victory over Leicester Tigers and a 32-23 semi-final triumph over Toulouse en route to their second Heineken Cup title last season.
Bath are now five points adrift but Ross said: "It was tough work - The Rec is a hard place to come away from with a win - and, although we probably left a few tries behind, getting the win was vital.
"And we expect nothing less than another hard fought game against them on Saturday. English clubs turn up whatever their position in the Pool and Bath will be no different."
And at the halfway stage of the group games there are only three clubs left with three from three - former double winners Munster at the top of Pool 1, Cardiff Blues at the head of Pool 2 and four times champions Toulouse leading Pool 6.
But the six automatic qualifying places as Pool winners and the best two runners-up places are still very much in the melting pot - no more so than in Pool 5 where only four points separate the four clubs in the wake of Benetton Treviso's 30-26 home win over Biarritz Olympique.