Glasgow win another penalty and set up camp in the home 22 once again.

Another try would put some daylight between the teams.

Scarlets defend really stoutly, though, with some dominant hits forcing Glasgow back, so Sione Tuipulotu grubbers into touch 12m from the Welsh line.

Kieran Hardy is on at scrum-half for Gareth Davies.

Sam Warburton
Former Wales captain on BT Sport

Glasgow have turned up the dial on the physicality, competing at the breakdown much better, mauling much more. They were trying to play too much in the middle 30 minutes, now they've gone back to meat and potatoes and they've got the upper hand now.

Instant influence from Matt Fagerson, who earns Glasgow a turnover penalty, over the top of Carwyn Tuipulotu.

Sam Wainwright returns from the sin bin, and Kemsley Mathias replaces Wyn Jones at loose-head prop.

Peter Wright
Former Scotland prop on BBC Radio Scotland

Because Glasgow are now four points in the lead, it puts a bit of pressure on the Scarlets game management.

When they get those kickable penalties, will they go for the posts or the corner?

Gareth Griffiths
BBC Sport Wales at Parc y Scarlets

Scarlets are in dire straits after Vaea Fifita trudged off the field injured.

He has been replaced by flanker Iestyn Rees with Sam Lousi now the only specialist second row remaining on the field for the home side.

Matt Fagerson is the next Glasgow man to emerge from the bench, replacing Sione Vailanu.

Gareth Delve
Former Wales international on BBC Radio Wales

You do wonder whether the injuries will take it's toll for the Scarlets. They've already had to make a lot of tackles.

Will that take its toll when Glasgow start to bring on those fresh legs?

Now Glasgow have a jackal penalty.

Sione Vailanu gets his 130kg Tongan frame over ball, and you'd need a Sherman tank to get rid of him in that position.

Glasgow go to the corner.

Johnny Matthews territory...

Peter Wright
Former Scotland prop on BBC Radio Scotland

Fifita is one of the best players in the league, he's an outstanding player, and a big loss.

Big minute there for Scarlets.

Johnny Matthews makes an immediate impact, scuttling deep into home territory.

Jack Dempsey carries further, but a couple of phases later, Matthews is isolated and guess who - Josh Macleod - gets his mitts on the ball.

Penalty Scarlets.

More concerningly, Dwayne Peel has lost yet another player. Vaea Fifita troops off grimacing, and Iestyn Rees comes on.

Franco Smith makes his first replacements of the day.

Jamie Bhatti and George Turner are taken off, with Nathan McBeth and try machine Johnny Matthews introduced.

Confidently done once more by Sam Costelow.

Scarlets lead again.

Four minutes of Wainwright's sin-bin period elapsed.

But here come the Scarlets!

Ioan Nicholas is caught high by Scott Cummings and the crowd are howling for a card.

Mathieu Raynal says penalty only, and Sam Costelow can nudge Scarlets straight back into the lead.

He sets up from around 25m out, a little to the left of the posts.

Gareth Delve
Former Wales international on BBC Radio Wales

Really important 10 minutes for Scarlets to manage this clock and get back to a full compliment with little damage done.

Chris Paterson
Former Scotland international on BT Sport

Sam Wainwright is always upright, there’s direct contact to the head, he’s very lucky that is not a red card.

For mitigation to apply there has to be a drastic change in height or direction from Rory Darge and I don't think either was drastic enough.

Peter Wright
Former Scotland prop on BBC Radio Scotland

The problem Scarlets have is that Wainwright is a tight-head prop so the first chance Glasgow get they should go for the scrum as Scarlets would have to go down to 13.

Colin Gregor
Former Glasgow Warriors back on BBC Radio Scotland

That is Warriors at their very best, going phase after phase, right to left, up the middle, giving the Scarlets no chance.

Double punishment for Scarlets, then.

Sam Wainwright does wrap his arms, which saves him from further punishment, but the giant tight-head is bound for 10 minutes in the bin.

Now George Horne, after several minutes of waiting, can line up the conversion attempt for his own try.