Tony Ward: Johnny Sexton can edge out-half duel to tip balance in Leinster's favour
So much for the posturing, this is the real thing. Leinster v Munster has been the biggest club rivalry in the world since the game went pro.
The numbers attending over the years bear that out, especially when the fixture is played at Lansdowne Road.
So for both squads and managements, regardless of caps or cups in the locker, the build-up to this game is different.
The intensity in both camps will have lifted dramatically over the last number of days without any coach having to set a new agenda. It happens as a matter of course.
This will be Test-level intensity. It is also Ireland's autumn international Final Trial in all but name, along with Connacht v Ulster last night.
The upcoming Champions Cup games will undoubtedly influence the Ireland think tank, but opportunity knocks in Dublin 4 today.
More than anything, this is about winning, about tribal bragging rights; get the collective performance right and individual aspirations will look after themselves.
So what can we expect? As ever, so much focuses on the rival No 10s: Tyler Bleyendaal in red and Jonathan Sexton wearing blue.
I still feel Ian Keatley is a better out-half than he is given credit for by Munster folk. However, his confidence has undoubtedly suffered on the back of topsy-turvy form, and all evidence suggests that Rassie Erasmus sees Bleyendaal as his main man.
The 26-year-old former Canterbury Crusaders out-half-cum-centre has been dogged by injury since arriving on these shores in early 2015.
He deserves a slice of luck and clear run to see if he can make the No 10 jersey his own, given Keatley's indifferent form allied to David Johnston's injury and Johnny Holland's sadly premature retirement.
It is too early in Bleyendaal's Munster career to form a definitive opinion; his competitive starts wearing No 10 are still in single figures but he is strong on the ball, a good distributor and likes to take the ball flat, thereby inviting those alongside on to the ball at pace for the potential off-load.
Stevie Crosbie has just signed as emergency cover, and I will be astonished if the former Ireland U-20 out-half doesn't push hard for the shirt, although like Bleyendaal he too is equally comfortable in the centre.
It was only six months ago that the talented Holland appeared to have announced his arrival on the big stage, scoring all 13 Munster points, including a try, in front of 43,000 people at a throbbing Aviva.
Holland was very good that night but guess who immediately opposite was even better? Yet another man of the match gong in another match-winning performance saw Sexton register all Leinster's 16 points, including his own try and the final pressure penalty to seal the deal.
Sexton is 31, so unlike Bleyendaal or Johnston, and indeed Paddy Jackson, time is not on his side.
I saw him quoted recently as saying: "I want to maximise my own playing time but be remembered as a good team player too."
I particularly liked the latter part of that comment, which I feel reflects a much more mature attitude.
Becoming a parent and hitting 30 are landmark stages in our lives. Sexton has experienced both of late and I suspect they have given him cause to reflect.
I mention the team player addendum because on the back of his cold and grumpy on-field persona, there is a perception that he is a self-absorbed star player.
That is certainly not the case. However, I wish he would smile more and at least appear to enjoy the ride a little better.
Indeed I wish I had done so myself in my own playing time, but this cover does not reflect the book, as almost everyone who has played alongside Sexton will testify.
He is a quality act who demands nothing of any other player he does not demand of himself.
This is a huge year for the Leinster playmaker, with Joey Carbery already making waves, Jackson offering a threat to his Ireland place and then the massive incentive of a Lions tour at the end of it all.
Factor in two shots at the Holy Grail that is beating the All Blacks, and the season could hardly be better set.
The Bleyendaal-Sexton head-to-head is central to today's outcome but it is far from the only clash of consequence.
Conor Murray is key. Along with CJ Stander he is the most important player in the Munster set-up, and certainly the most influential back.
The Reds can manage without Donnacha Ryan, Peter O'Mahony, Tommy O'Donnell and other international players of that ilk, but they struggle when Murray is absent.
Leinster are red-hot favourites but don't dismiss the improbable.