Sexton's experience gives Leinster derby edge
The capacity of these teams to dominate the national debate has ebbed with their inability to conquer Europe but, while the audience may not be what it once was, the importance of this clash of red and blue is as high as ever.
Next week, Europe moves on without the teams who won the Heineken Cup five times between 2006 and 2012 and the path back to the top begins with the Guinness Pro12.
The tournament was almost an afterthought during those heady days, but times have changed and suddenly seasons are being defined on nights like tonight.
The sight of Connacht on top of the league cannot sit well with these two big guns, while the impending arrival of Charles Piutau and Marcell Coetzee at Ulster is another worrying sign that the landscape has changed in recent years.
Both provinces have looked to the future, Leinster have Robbie Henshaw on the way while Munster are searching for a director of rugby, but the need to finish this season strongly is great and it is the southern province who will be in greater peril if they can't get a result at the Aviva Stadium this evening.
Currently fourth, seven points adrift of tonight's opponents, three of their four remaining games come against the top-three with an Edinburgh side who are still in the hunt making up the rest.
Second-placed Leinster may have lost two on the trot, but Leo Cullen's side's run-in looks easier and a victory at the Aviva Stadium would give them some breathing space despite their loss to Connacht last weekend.
Cullen has been able to add plenty of fire-power to his side, recalling Johnny Sexton, Jamie Heaslip, Jack McGrath and Eoin Reddan, but Rob Kearney and Luke Fitzgerald are kept on ice and Jordi Murphy is preferred to Josh van der Flier at openside.
Anthony Foley, meanwhile, has taken a gamble by picking Johnny Holland at out-half. The 24-year-old Cork native made just his second start in the position last weekend against Zebre but has been trusted with leading an impressive-looking backline in what will be by far the biggest occasion of his career to date.
Opposite him is the Ireland and Lions No 10 who has had a week's rest after an excellent Six Nations campaign. For all that Holland is a fine place-kicker and a decent prospect, there is a gulf in class between the out-halves.
Leinster were full of compliments for the youngster at their press briefing yesterday, but you can be sure that Rhys Ruddock, Murphy and Heaslip will be making bee-lines for his channel to see what he's about.
That looks to be the most obvious difference between the two teams, although Leinster's bench looks to have a bit more impact than their opponents.
It may well come down to the battle up front with the forecast for difficult conditions. Leinster appear to have the edge, with six Ireland front-rows with experience from this year's Six Nations to call on, with the seconds and back-rows relatively evenly matched.
There is plenty of talent behind the scrum, but conditions may deprive the big crowd of fireworks. Control will be key and Johnny Sexton's ability to deliver could be the difference.
LEINSTER - Z Kirchner; I Nacewa (capt), G Ringrose, B Te'o, D Kearney; J Sexton, E Reddan; J McGrath, S Cronin, T Furlong; D Toner, H Triggs; R Ruddock, J Murphy, J Heaslip. Reps: R Strauss, C Healy, M Ross, R Molony, J van der Flier, L McGrath, I Madigan, F McFadden.
MUNSTER - S Zebo; A Conway, F Saili, R Scannell, K Earls; J Holland, C Murray; J Cronin, N Scannell, S Archer; D Ryan, B Holland; D O'Callaghan, T O'Donnell, CJ Stander (capt). Reps: M Sherry, D Kilcoyne, J Ryan, R Copeland, J O'Donoghue, T O'Leary, I Keatley, D Sweetnam.
Referee - I Davies (Wales)
Live Sky Sports 3, TG4 5.30pm