Good evening and welcome to rugby’s semi-final weekend.

We’re gonna talk you step-by-step through Leinster’s Pro12 clash with Scarlets (you’ve still got about 30 minutes to find and plonk yourself in front of a TV with Sky Sports 1).

Before we start though, news from the Champions Cup play-off semi-finals: Stade Francais have beaten Cardiff Blues and so will face either Connacht or Northampton next week to decide who gets the 20th and last place in next season’s European Cup.

Here are your teams for tonight and a reminder, in case you missed it this afternoon, that Sean O’Brien has been withdrawn from the matchday 23 with a calf issue.

Leo Cullen had initially gone with a 6/2 split on his bench, but out-half Ross Byrne has taken O’Brien’s spot in the replacements.

Scarlets boss Wayne Pivac has been able to name the excellent poacher James Davies in his back row after injury, so watch out for him and ex-Leinster lock Tadhg Beirne  and their efforts to disrupt the Leinster breakdown.

Leinster:

15. Joey Carbery
14. Adam Byrne
13. Garry Ringrose
12. Robbie Henshaw
11. Isa Nacewa (captain)
10. Johnny Sexton
9. Luke McGrath

1. Jack McGrath
2. James Tracy
3. Tadhg Furlong
4. Ross Molony
5. Hayden Triggs
6. Rhys Ruddock
7. Josh van der Flier
8. Jack Conan

Replacements:

16. Richardt Strauss
17. Cian Healy
18. Michael Bent
19. Devin Toner
20. Dan Leavy
21. Jamison Gibson-Park
22. Ross Byrne
23. Zane Kirchner

Scarlets:

15. Johnny McNicholl
14. Liam Williams
13. Jonathan Davies
12. Scott Williams
11. Steff Evans
10. Rhys Patchell
9. Gareth Davies

1. Rob Evans
2. Ryan Elias
3. Samson Lee
4. Lewis Rawlins
5. Tadhg Beirne
6. Aaron Shingler
7. James Davies
8. John Barclay (captain)

Replacements:

16. Emyr Phillips
17. Wyn Jones
18. Werner Kruger
19. David Bulbring
20. Will Boyde
21. Jonathan Evans
22. Hadleigh Parkes
23. DTH Van Der Merwe

Conor McGregor’s anthem, The Foggy Dew, echoes around the RDS to signal Leinster’s entrance to the field.

“Let’s go,” says Isa to the mascot, but he’d say the same to anyone in front of him.

KICK-OFF:

Leinster’s first few minutes of this game are immensely encouraging. Very productive set of phases that brings them into the 22, only a whipped pass from Sexton to Nacewa brings the momentum to an end as it flew forward.

A brief burst for Scarlets as Sexton is smashed, but the turnovers don’t end there. A frenetic pace to this game – not least because of Tadhg Furlong’s willingness to fling the ball 20 metres right of a ruck into the path of Garry Ringrose.

TRY! Leinster 0 Scarlets 7 (Evans ’9)

Glorious score from the visitors as Jonathan Davies brushes aside Adam Byrne to set Steff Evans away down the left.

Injury to insult for Leinster then, Jack McGrath called ashore and replaced by Cian Healy. Had his elbow strapped from early stage.

Here’s a look at that excellent Scarlets try.

PENALTY! Leinster 3 Scarlets 7 (Nacewa ’20)

JVDF carries and forces a penalty for not releasing. Sexton gets a bit of treatment as Nacewa steps up to place the ball on the tee.

Ooomph! Jack Conan (and an assistant) hit oldboy Tadhg Beirne with an almight hit and drive to plough him backwards.

Luke McGrath pounces on a loose pass that follows and he looks to be off under the posts, but Liam Williams hares back to deny the scrum-half.

TRY! Leinster 8 Scarlets 7 (Ringrose ’23)

Magnificent set move from Leinster, big men hitting up twice off a line-out maul and Ringrose taking Jack Conan’s offload all the way to the house.

The conversion comes to give Leinster breathing space.

Leinster 10 Scarlets 7

TRY! Leinster 10 Scarlets 14 (Shingler)

Shingler manages to step through the line, passes left and gratefully takes the return pass and plants a big hand on the chest of Gibson-Park to keep the Kiwi at bay and ground a second try.

Patchell drops the conversion before any pesky TMO can get a look in.

TRY! Leinster 10 Scarlets 21 (Gareth Davies 30)

This is incredible stuff from the visitors, they pour through the blue lines again with offloads from Scott Williams and James Davies before Steff Evans flicks it inside for the scrum-half to finish.

Leinster have never lost a Pro12 semi-final, no home side has lost a Pro12 semi. But Leo Cullen’s side are 11 points downe and being out-muscled and out-run here.

Johnny Sexton has to dot down behind his line. He runs to the 22 to restart and Gareth Davies gets into a grappling match with him.

A scuffle ensues.

God, semi-finals are great aren’t they!

RED CARD! Steff Evans

Leinster get their off-loading game going and Ringrose makes a dart at the 22. The centre looks for the ground to recycle, but there’s a twisting tackle involved and Ringrose’s head hits the ground first.

HALF-TIME: Leinster 10 Scarlets 21

Scarlets were brilliant in the first-half, but they’ll have to be twice s good in the second period after that red card.

Here’s the tackle that ended with a straight red card for Scarlets star Steff Evans.

Here comes the second half then.

Can Scarlets hang on… for long?

Amid all the drama of the first half we may have neglected to mention that Luke McGrath is off permanently after his HIA. So Gibson-Park will finish this game  out.

Scarlets have kept their cool in the second half. A fine breakdown penalty won and they patiently go through phases in enemy territory.

A grubber through the line gives possession away, but JGP blasts a kick out on the full.

No shortage of dynamism in Leinster’s back row now. Rhys Ruddock has been called for HIA so Dan Leavy will add his energy alongside JVDF and Jack Conan.

Terrific defence from Scarlets after Leinster look to up the tempo and Ringrose steps in and through tackles.

Scott Williams forces a penalty to help clear the lines.

Hayden Triggs gets a warm round of applause as Devin Toner is unleashed.

If Scarlets were cursing Marius Mitrea at the break, they can thank him for a fortunate turn of events there.

Joey Carbery ran into the referee, armless tackle could’ve been a yellow, and the red pack then mined a scrum penalty on the resulting set-piece.

Leinster maul does serious work in their 22 though to plough the Welshmen out.

Ringrose, as is his wont, flies out of the line and makes a fine hit to rock Scarlets in their 22.

Unfortunately for Leinster, JGP tries to make an instant score by flicking the ball to the blindside.

Patience will get Leinster the scores they need here. Patience and forward power.

Tadhg Furlong makes big yards in midfield, but he comes away from the ruck with a very heavy limp.

Scarlets defence still performing brilliantly and bringing deep frustration and errors from Leinster.

60 mins: Furlong walks off with some assistance, Michael Bent is in the game.

TRY! Leinster 15 Scarlets 21 (Conan ’54)

Scarlets overthrow a line-out horribly in their own 22 and James Tracy grabs and goes.

Leavy carries from five metres and a small dent is all the invitation Jack Conan needs to barge over.

The momentum shift is not total however. Inexplicably, Isa Nacewa blasted the easy conversion off the post. So there is still a six-point deficit for the home side.

12 minutes and six points to go for Leinster.

Scarlets go up the other end and force a penalty. Liam Williams steps up AND NAILS IT!

PENALTY! Leinster 15 Scarlets 24 ( Williams ’70)

Such drama. Such tension. Leinster mount an attack in the 22 again, JVDF bulldozes his way through tacklers, but the defence is still standing.

Garry Ringrose withdrawn with seven minutes to go. Zane Kirchner is sent into the fray.

That feels like a very odd call.

We’re inside the final five minutes and Scarlets are so close to becoming the Pro12′s first away winner of a semi-final they can taste it.

Errors are coming thick and fast from Leinster and the RDS is deathly quiet.

PENALTY! Leinster 15 Scarlets 27 (Williams ‘ 79)

FULL-TIME! Scarlets are in the Pro12 Grand Final after beating Leinster 15 – 27.

They had 14 men for over 40 minutes, but beat Leinster 5 – 6 in the second half.

That’s all from me, folks, and that’s all from Leinster for this season.

Scarlets are in the Pro12 final in the Aviva Stadium next weekend. Munster will take on Ospreys tomorrow hoping to prevent an all-Welsh final in Dublin.