Ben Breakspear was close and said that there was no clear knock-on but the decision has been changed.

No try but Henry Thomas is penalised and Cardiff will have another crack.

Cardiff's kicking game earns a penalty that Callum Sheedy kicked towards the 22.

They hammer towards the line but Josh Macleod gets over the ball.

Cardiff were playing with penalty advantage. They will go for a tap move.

Play has been almost exclusively between the two 10-metre lines so far.

Some aggressive defence and serious competition in the air. Both teams happy to use the boot in these early stages.

James Hook
Former Wales fly-half on BBC Two Wales

The Arms Park feels electric tonight, with Cardiff on great form against a strong Scarlets pack that are going to ask questions of Cardiff this evening.

Referee Ben Breakspear blows his whistle and Scarlets fly-half Joe Hawkins gets us under way.

Cardiff attack the Taff end in the first half.

It was lively in Cardiff with rugby fans mixing with office parties.

The supporters have slowly made their way to the terraces and seats, with a sizeable Scarlets contingent opposite us in the Peter Thomas Stand.

They give a quick rendition of 'Sosban Fach' before the visitors are first to head out to the field, led by Josh Macleod.

Cardiff follow with fit-again Liam Belcher leading them out through the smoke and blue lights.

Image source, Huw Evans Picture Agency

Taulupe Faletau is back on the bench to give Cardiff a lift but don't underestimate the importance of the starting number eight.

Alun Lawrence has been a real force for the Blue and Blacks this season, and he leads the United Rugby Championship for carries (102) and tackles (95).

"It’s just doing my job, my role within the team, whether that is ball-carrying, whether that is tackling," he said.

"I will always put myself in positions to contribute, however I need to contribute.

"I don’t set myself personal targets where I need to make X amount of carries or tackles for me to think I’ve had a good game.

"Sometimes you have a lot of involvements, other times you have slightly less, but you are still contributing and still doing your job.

"A big driving factor for me is how I can execute my role repeatedly really well, more than setting myself personal targets."

A sign of the dependable forward's influence is that dynamic flanker or number eight Taine Basham, a summer signing from Dragons, misses out on the 23... perhaps held back for a 26 December reunion with his former team-mates.

Image source, Huw Evans Picture Agency

Cardiff have given their fans plenty to cheer about at the Arms Park this season but this evening they will have to drown out a sizeable away following.

Scarlets always travel in big numbers for this fixture, although plenty are making shorter journeys.

"Over the other side from the tunnel there is always a sea of Scarlet," said head coach Dwayne Peel.

"What did the PA announcer say last year? 'Scarlets fans have a safe trip back home to Pontcanna'.

"There are a lot of West Walians living in Cardiff and it is always a well-supported match for us.

"Our fans travel well, we had something like 500 in Bordeaux, it was class to see them. Their support is so important for us and to put on a show for them is important for us."

Image source, Huw Evans Picture Agency

Cardiff have a perfect record at the Arms Park this season but will be trying to end a poor run against their rivals from Llanelli.

Scarlets have won the last four games against the Blue and Blacks in the capital, a run that goes back to a defeat in January 2021.

That fixture was played at Cardiff City Stadium because the Arms Park was used as a field hospital during the Covid pandemic.

The Blue and Blacks haven't beaten Scarlets at the Arms Park since March 2019, when they won thanks to tries by Owen Lane (2), Aled Summerhill (2) and Josh Turnbull.

Cardiff's only survivor in today's matchday 23 is lock Rory Thornton, who is on the bench.

We've got all the bases covered for you this evening, with our live text backed up by both Scrum V Live's tv coverage and radio commentary from BBC Radio Wales Sport - just use the 'Watch & Listen' tab near the top of the page to pick your poison!

Some pre-match stats ahead of tonight’s game courtesy of the United Rugby Championship:

• Cardiff have won five of their opening six URC fixtures, including their last four. They have not won five in a row since 2018.
• Cardiff have won their last six home games in all competitions since their loss to Sharks at the Arms Park in January.
• Scarlets beat Glasgow 23-0 in round six to end a run of six successive defeats in the URC.
• Dwayne Peel’s side have lost their last four away fixtures in the URC since they beat Lions 32-19 in Johannesburg in May.
• Scarlets have won their last three URC matches against Welsh sides.

Image source, Huw Evans Picture Agency

Scarlets are boosted by the return of Wales full-back Blair Murray, who missed both Euorpean Champions Cup defeats to Bristol and Bordeaux-Begles through injury.

Peel rotated his squad for the 50-21 loss in France and brings back wing Tom Rogers, centre Johnny Williams and scrum-half Gareth Davies.

Centre or fly-half Joe Hawkins continues in the 10 jersey in the absence of Sam Costelow, whose ankle injury suffered in training this week could lead to a United Rugby Championship debut off the bench for academy prospect Elis Price.

Loose-head Kemsley Mathias, hooker Ryan Elias, tight-head Archer Holz and lock Sam Lousi return to the XV, with Max Douglas and captain Josh Macleod switching to blind-side and open-side flanker.

There are a couple of late changes on the bench with Tristan Davies and Macs Page included.

Scarlets: Murray; Rogers, James, J Williams, Mee; Hawkins, G Davies; Mathias, Elias, H Thomas, Lousi, Ball, Douglas, Macleod (capt), Anderson.

Replacements: Van Der Merwe, Hepburn, H O'Connor, T Davies, Taylor, A Hughes, Price, Page.

Image source, Huw Evans Picture Agency

Cardiff captain Liam Belcher has recovered from the neck injury that ended his autumn campaign with Wales early.

He starts at hooker in between props Danny Southworth and Javan Sebastian as coach Corniel Van Zyl freshens up his pack, with dependable lock Josh McNally also restored.

Wing Mason Grady and full-back Cam Winnett also come into the XV from the dramatic win against Ulster in the European Challenge Cup.

Cardiff go for six forwards on their bench - with legendary Wales number eight Taulupe Faletau set for a cameo.

He has been out of action since suffering a knee injury against Edinburgh that ruled him out of Wales' autumn campaign.

Cardiff: Winnett; Adams, Millard, B Thomas, Grady; Sheedy, A Davies; Southworth, Belcher (capt), Sebastian, McNally, Nott, Botham, D Thomas, Lawrence.

Replacements: E Lloyd, Barratt, Wainwright, Thornton, Mann, Faletau, Mulder, Beetham.

Image source, Huw Evans Picture Agency

Welcome to the Arms Park for what promises to be a terrific Welsh derby between Cardiff and Scarlets.

The hosts have been the surprise package in the United Rugby Championship this season and will leapfrog Stormers into first place in the table if they make it six wins out of seven.

The visitors endured a tough start to the campaign but have shown signs of life since the break for the autumn internationals.

Scarlets beat Glasgow in the URC and then emerged with credit from Champions Cup defeats to Bristol and Bordeaux-Begles.

Dwayne Peel’s side have a strong record in Cardiff and this is a tough one to call, so let’s have a look at the teams.