Postpublished at 45 mins
Scarlets 14-12 Glasgow Warriors
Right, we're checking a high tackle from Scarlets prop Sam Wainwright on Rory Darge.
Final score: Scarlets 17-35 Glasgow
Warriors book first European final - on 19 May in Dublin
Glasgow will play Toulon or Benetton in final
McDowall (2), Horne, Matthews & Darge score tries for Glasgow
Four Costelow penalties & Evans try for Scarlets
Scarlets lose four players to injury - Sebastian, Williams, Jones, Fifita
Jamie Lyall
Scarlets 14-12 Glasgow Warriors
Right, we're checking a high tackle from Scarlets prop Sam Wainwright on Rory Darge.
George Horne
Brilliantly worked score for Glasgow Warriors. Tremendous line-breaks from Jack Dempsey, then JP du Preez, open the door.
The 6ft 11ins South African flips on to Scott Cummings, who sends George Horne scurrying home.
In the middle of all that, TMO Eric Gauzins was alerting Mathieu Raynal to some element of foul play.
The comms between TMO and referee weren't working, so having given the try, Raynal trots towards the big screen to spool through the footage.
Scarlets 14-7 Glasgow Warriors
Glasgow start the second half with a spree of attacking phases just inside the Scarlets half.
Sione Vailanu looks hungry, making three telling ball-carries.
Scarlets 14-7 Glasgow Warriors
Let's get to it, then.
Forty minutes for one of these teams to book their place in a maiden European final.
HT: Scarlets 14-7 Glasgow
Gareth Griffiths
BBC Sport Wales at Parc y Scarlets
Wales coach Warren Gatland and his staff are here to watch this game ahead of the extended World Cup training squad being announced on Monday.
So a last chance for hopefuls to impress.
HT: Scarlets 14-7 Glasgow Warriors
A terrific first half from the Scarlets kingpin, Josh Macleod.
Three turnovers at the breakdown and more tackles - 10 - than anybody else.
The teams are back out for the decisive second 40 minutes.
HT: Scarlets 14-7 Glasgow Warriors
The game's top carrier so far is Glasgow prop Zander Fagerson.
He has carried with huge dynamism this season and that belligerence is on full display again in the Llanelli sunshine.
The big man has made 10 carries already, gaining 15m, and won a couple of scrum penalties too.
HT: Scarlets 14-7 Glasgow
Gareth Griffiths
BBC Sport Wales at Parc y Scarlets
Scarlets will take that 14-7 half-time lead after the opening quarter that Glasgow dominated.
Flanker Josh Macleod and Dan Davis have helped turned the tide with their breakdown work and Scarlets have put Glasgow under pressure.
Glasgow are determined to stick to the running style that has served them so well this season.
A fascinating second half awaits.
Scarlets centre Scott Williams on S4C:
"Glasgow had a great start with that try at the start of the game, but Scarlets have bounced backed well.
"We need to work a bit on our defence and then hopefully we'll go even better."
HT: Scarlets 14-7 Glasgow Warriors
The half-time stats make for interesting reading.
Glasgow have enjoyed more possession, but Scarlets have had the bulk of territory - 62% of it, in fact.
Scarlets have made roughly half as many carries as Glasgow, but missed an ugly 18 of their 109 attempted tackles. Barring the Stafford McDowall try, it hasn't really cost them.
The Warriors have put themselves under pressure on several occasions, and a ropey line-out will be high on Franco Smith's list of priorities at the interval.
The visitors have won only five of their nine throws so far.
The bold Sheriff and his pals will be happy with how this one is tracking.
HT: Scarlets 14-7 Glasgow
"Glasgow don’t want rucks, they don’t want to bring Dan Davis and Josh Macleod into the game," says former Ospreys coach Sean Holley on BT Sport.
"They want to move the ball around and keep it away from the Scarlets flankers."
Peter Wright
Former Scotland prop on BBC Radio Scotland
That's a dreadful decision. That's no different to what the Scarlets boys have been doing to steal the ball.
He's penalised Jamie Bhatti, it's really hard for the referees because the pace of the game but I think that's a really poor decision.
What a frenetic first 40 minutes at Parc y Scarlets.
Glasgow came rampaging out of the traps, Stafford McDowall blasting home inside five minutes after some excellent build-up, handling and power.
Since then, though, it's been all Scarlets.
The penalty count has climbed as Glasgow compounded error with infringement.
Sam Costelow banged over two three-pointers, before Glasgow mess up a line-out, Scarlets pinch the ball, and Steff Evans winds up with a simple run-in.
Costelow's kick right on half-time gives the hosts a seven-point lead at the break.
As things stand, the Scarlets are heading for Dublin and their first European final.
Some second 40 in store...
Sam Costelow
Over it goes, and that's half-time.
Scarlets 11-7 Glasgow Warriors
Jamie Bhatti is penalised for not supporting his own weight at the breakdown, and Sam Costelow lines up a straightforward goal from beneath the shadow of the Warriors posts.
Scarlets 11-7 Glasgow Warriors
Penalty advantage Scarlets. Here we go...
Colin Gregor
Former Glasgow Warriors back on BBC Radio Scotland
Warriors lose the ball in contact and they've got no-one in the backfield because Kyle Steyn's taken the up and under and Costelow makes them pay with a fantastic kick.
Scarlets 11-7 Glasgow Warriors
Ooft, an incredible take from Kyle Steyn moves Glasgow into the Scarlets half for the first time in a while.
From the next phase, though, Warriors lose possession and there's a terrific kick from Sam Costelow bobbling into the away 22.
It's a 50-22, meaning Scarlets will throw in at the line-out.
Two minutes til half-time. Can they stretch that lead?
Scarlets 11-7 Glasgow Warriors
Morgan Jones is off after copping that heavy Fagerson hit to the head.
On comes Carwyn Tuipulotu, cousin of Glasgow centre Sione, with Vaea Fifita moving from number eight to the second-row.
That's a third injury-enforced Scarlets sub.
Colin Gregor
Former Glasgow Warriors back on BBC Radio Scotland
Morgan Jones just gets his head on the wrong side.
A little bit of footwork from Fagerson gets the Scarlets second-rower in the wrong position.