Welcome along to the most important event at the RDS this weekend. That’s right Fianna Fáil, you heard me!

A bit of cloud cover but, otherwise, a glorious day in Dublin. Lions forwards coach Graham Rowntree is in town and gave me a knowing nod as he sauntered by me earlier, cauliflowered ears and all. He would have liked to check out Sean O’Brien today but the back-row is ruled out. Here is the Leinster team:

Leinster: R Kearney; F McFadden, B O’Driscoll, I Madigan, I Nacewa; J Sexton, I Boss; C Healy, R Strauss, M Ross; L Cullen (c), D Toner; K McLaughlin, S Jennings, J Heaslip.

Replacements: S Cronin, J McGrath, J Hagan, Q Roux, R Ruddock, J Cooney, A Goodman, A Conway.

Here is the Biarritz matchday 23. Not too shabby:

Biarritz: Marcelo Bosch; Taku Ngwenya, Benoît Baby, Damien Traille, Aled Brew; Jean-Pascal Barraque, Dimitri Yachvili; Thomas Synaeghel, Arnaud Heguy, Ben Broster; Erik Lund, Pelu Taele; Thibault Dubarry, Raphael Lakafia, Imanol Harinordoquy.

Replacements: Benoit August, Eugène Van Staden, Francisco Gomez Kodela, Mathias Marie, Wenceslas Lauret, Yann Lesgourgues, Seremaïa Burotu, Teddy Thomas.

I’m going to leave the cosy confines of the press room and take my seat in the stands. I’ll leave you for now by asking who you think will win this tie. Feel free to expand on your theories in our comments section, below.

Leinster going through a rigorous work-out in front of a South Stand that is starting to fill up. 10 minutes away from kick-off as the enthusiastic stadium announcer goes through the home team starting XV. Isa Nacewa gets the biggest cheer.

G’wan The Coronas. The PA belts out an easy-listening pop classic from Danny and the boys as the ground fills up to near capacity. Some spots in the North Stand corners [where I watched Leinster lose a Pro12 Grand Final to Ospreys from].

Here come the teams. Leinster in their ‘Heineken Cup’ strip.

KICK-OFF

O’Driscoll links up with Nacewa up the left wing but Wayne Barnes ends the attack by penalising the Kiwi for not releasing.

Biarritz piling into Leinster inside their 22 but the home defence is solid and McLaughlin gets the back slaps as he emerges from the ruck with Barnes penalising the French side.

TRY! Leinster 5-0 Biarritz [Heaslip '3]

One of the best tries you’ll see all year. Classic training ground move as Strauss overthrows deliberately to Toner at the back of the lineout. He pops it straight up for the charging Nacewa, who races up the left and finds Heaslip in support. The Ireland captain has the gas to beat two covering defenders out wide before arching in and dotting down. Sexton converts. Super start for Leinster.

Cian Healy is playing the loose forward role as he steals near a Biarritz ruck and charges forward. The move spins out left but Madigan knocks on and the French side get a free-kick after an early scrum engagement. Good kicking from Kearney then has Bosch scrambling and the Blues get another attacking lineout.

Here was the scene at the RDS on kick-off:

The sun shines on D4. (Credit: Patrick McCarry)

Some antics at the breakdown as Cullen gets caught up in some pushing and shoving. Barnes call play back for an earlier Leinster advantage but Sexton’s penalty skitters left and wide. Still 7-0 after 13 minutes.

TMO. Brilliant O’Driscoll break and he feeds the charging Sexton but, one yard short of the line, N’Gwenya snaffles him up. They roll over the tryline but the decision is ‘held up’. No try

PEN: Leinster 7-3 Biarritz [Yachvili '19]

After the success of the first lineout move, Leinster try another long throw but it finds no-one and is eventually snapped up by Lakafia. Quick passes before N’Gwenya races up the middle, gaining 30 metres in no time. A scrambling Leinster concede a penalty and Yachvili gets his side on the scoreboard.

O’Driscoll shoots out of the defensive line but is evaded by Baby before Madigan cleans up and dumps the centre to the ground. Great work by Jennings at the breakdown gets Leinster a penalty and Sexton finds touch on halfway. Another lineout goes awry, however. The ball is kicked to Kearney, who marks it, but his kickback is straight up the middle and untroubling. Biarritz trundle forward again.

PEN: Leinstyer 7-6 Biarritz [Yachvili '24]

Barnes penalises Leinster as Biarritz power straight up the guts and dangerously close to the posts. Taele and Dubarry doing well there. Yachvili’s penalty is chipped over the bar.

PEN: Leinster 10-6 Biarritz [Sexton '28]

Wayne Barnes that is some fine referee camer-work. Nice footage of a Leinster scrum on the big screen. Heaslip just about presents for Boss as Yachvili snaps at his heels. Harinordoquy with the 25 jersey on him after getting his 8 kit bloodied. Biarritz concede a penalty 10 metres from their sticks and Sexton, not messing about, puts it over and into Row T.

Isa Nacewa lucky not to concede a penalty twice in 10 seconds as he fails to release Bosch in the tackle, eventually lets go and comes in from the side. Barnes says play on and the Frenchmen derail their attack by sloppy passing and a knock-on. Scrum Blue in the home side’s 22.

Heaslip must have read on this liveblog, which I’d imagine he reads right before kick-off, that Lions forwards coach Graham Rowntree is in the ground. He’s playing like Heaslip circa 2008-09. Another marauding run as he dashes out of his 22 and carries for 30 metres. He wins his side a penalty on halfway. Sexton opts for a crossfield kick that Nacewa almost clinches. He is first up to dive on the bouncing ball but is isolated, held up, and Biarritz get, then win, a scrum. Five minutes to HT.

PEN: Leinster 10-9 Biarritz [Yachvili '38]

Yachvili gets a shot at the sticks and it looks like Nacewa is the man getting penalised for a deliberate knock-on. I’ll try to clarify that. The scrum-half slots over from 40 metres out and slightly to the right.

TRY! Leinster 17-9 Biarritz [Sexton '39]

Rob Kearney takes a pass on the charge, evades to defenders and unselfishly slips in Sexton, who tangles with N’Gwenya again but touches down unfettered this time. He takes the congratulations before converting.

Just before the HT whistle Leinster get a penalty and choose to quick-tap rather than kick. It works out amazingly well…

TRY! Leinster 24-9 Biarritz [Heaslip '40]

The big man strikes again as a superb, all-out Leinster attack is rewarded. Heaslip spots a gap, charges straight up the centre and holds of N’Gwenya to stretch over and touch down. In three minutes Joe Schmidt’s men look to have settled this semi-final.

HALF-TIME

What did you make of that half? Leinster, I feel, are enjoying playing without shackles and going for broke. Heaslip and Healy have been fantastic.

Nacewa beats Imanol Harinordoquy of Biarritz Olympique. (©INPHO/Dan Sheridan)

The Leinster players from Ireland Women’s Grand Slam-winning squad have received a warm ovation from the home crowd as they show off their Six Nations trophy. Live it up ladies, live it up.

2nd HALF KICK-OFF

Jonny gets us underway.

Kevin McLaughlin is coming off after receiving on-field treatment for a while. Rhys Ruddock is on.

Isaac Boiss box kicks very well and he puts up a great ball that Nacewa almost claims. Aled Brew then zooms past Mike Ross and is finally hauled down on halfway. Leinster concede a penalty but Yachvili can’t make the home side pay.

PEN: Leinster 27-9 Biarritz [Sexton '45]

We were then almost treated to one of the tries of the season but Madigan, after an intercept and 78 metre sprint, runs out of gas and is hauled down by N’Gwenya. The American winger does not release, with Sexton and O’Driscoll screaming at the referee. He gets sin-binned and Sexton chips over a simple penalty.

Kearney hares after Bosch following a Nacewa grubber kick but play is called back as the Leinster fullback was a hair’s breadth ahead of his teammate as he kicked. Just to confirm, N’Gwenya got a yellow card

Sky Sports cameras have located Graham Rowntree, Neil Jenkins and Rob Howley in the stands. Warren Gatland’s scouts on patrol.

TRY! Leinster 34-9 Biarritz [Nacewa '49]

The Blues are slicing through the deflated French now. Sexton and Nacewa play a couple of one-two passes to flummox Brew and Bosch, allowing the winger to race clear and touch down. Sexton is coming off now, walking gingerly, so Madigan converts.

McFadden then shows up with an excellent break, claiming his own chip before O’Driscoll muddies the attacking waters and the chance is lost.

McLaughlin is back on as Goodman replaces Sexton. Attacking scrum on the Biarritz 10m line. 25 minutes left.

PEN: Leinster 37-9 Biarritz [Madigan '56]

Great break from Boss as he goes close to a try, with Harinoruqoy lax in the tackle. N’Gwenya back on but another penalty is conceded in front of the posts and Madigan easily converts.

The French side are not the only ones to be having a rough Saturday.

A little bit of afters between Strauss and Biarritz sub Yann Lesgourues as Boss and McFadden lie injured. They are slow to get up but good to continue. Wait, quintuple substitution for Leinster! Whole new from row, Quinn Roux for Cullen and John Cooney for Boss.

A minute before the changes were made, Madigan shaped to kick before jinking inside his man and gaining some yards. He can really play anywhere in that Leinster backline. 63 minutes gone.

TRY! Leinster 39-9 Biarritz [O'Driscoll '64]

The cries of ‘One more year’ ring around the RDS for O’Driscoll as he sits back and reflects on his try, which came after a stunning charge from Sean Cronin. Madigan with another conversion.

TRY: Leinster 44-16 Biarritz [Heguy '68]

Lund sets up the hooker and he gets by Cooney, the only covering defender, to score. Yachvili converts.

N’Gwenya goes by Kearney and shows him his heels before Ruddock mops up with a covering tackle. Into the final 10 minutes here. Heaslip is my bet for man-of-the-match but Madigan, Sexton, Healy and Nacewa would all be up there too. Who would you choose?

Howley, Jenkins and Rowntree are off. They’ve seen enough. Big green ticks beside the names Healy, O’Driscoll, Sexton, Heaslip and possibly Kearney. Madigan’s name underlined three times!

Harinordoquy is cheesed off and lumps a touchline marker into the stands, much to the amusement of the crowd in the Grandstand. Leinster attack off a claimed lineout and are in range to perhaps nick try number six. Three minutes left and Goodman is back on his feet after receiving treatment.

Heaslip gets the sponsor’s Man-of-the-Match award and walks off to a standing ovation from a large chunk of the crowd.

O’Driscoll tries to link up with Nacewa but is called for a forward pass. Last action of the game. That was a beat-down.

FULL-TIME