Jason Tovey has gives Cardiff Blues victory with a penalty in the dying minutes
The hosts led 10-6 at half time
Cardiff Blues Josh Adams, Filo Paulo and Tomos Williams sin-binned, but an Evans try put them ahead before Marty McKenzie levelled
Sam Davies drops the winning goal against Scarlets with the final kick of the game for Dragons after missing with a penalty minutes earlier
It was Dragons second successive win over Scarlets, having lost the previous nine
Dragons 16-17 Scarlets
Nick Webb
BBC Sport Wales
That was an extraordinary dummy from Rhodri Williams, I was looking for him to pass that out to Sam Davies and the backline.
Having started the game with a shocker he's now on the score sheet.
Dragons 16-17 Scarlets
A try against his former team for Dragons captain and scrum-half Rhodri Williams!
After a period of concerted pressure from the hosts, Williams dummies and makes his way over from close range. Fine finish.
A bit of a melee ensues and Scarlets prop Wyn Jones is sent to the sin-bin.
Dragons 9-17 Scarlets
Adrian Hadley
Former Wales international on BBC Radio Wales
It looked as though the Dragons had stopped it, then a second drive of momentum has pushed them 15 metres for that try.
It's been a very very expensive 10 minutes for Dragons with that sin- bin. With two tries, Scarlets seem to be taking control of this game.
Dragons 9-17 Scarlets
Scarlets take full advantage of their extra man in the pack with an impressive rolling maul.
It rumbles in from at least 20 yards and the man at the bottom of it all, with his hands on the ball for the try, is hooker and captain Ken Owens.
Leigh Halfpenny converts well from the left and Scarlets are now 17-9 up.
The visitors have scored 14 of their points with Dragons' Matthew Screech in the sin-bin.
Dragons 9-10 Scarlets
That man knows his way to the try line!
A sniper whether he plays for Wales or Scarlets, scrum-half Gareth Davies darts over from a scrum to score the game's first try.
Leigh Halfpenny converts from close range and Scarlets now lead.
Fly-half Dan Jones, meanwhile, is forced off with an injury and the veteran Ryan Lamb is on in his place.
Image source, Huw Evans Picture AgencyDragons 9-3 Scarlets
Dragons lock Matthew Screech is shown a yellow card for entering from the side.
The home side will be down to 14 men for the next 10 minutes.
Adrian Hadley
Former Wales international on BBC Radio Wales
If only the passes would have gone to hand, I think it was Wainwright, and it's gone between the two Dragons players outside him. In fairness he had to get rid of it quickly but if that had gone to hand it would have been a try.
Dragons 9-3 Scarlets
Great play from the home side. Dragons scrum-half Rhodri Williams starts it all with a darting run into the 22 of his former side.
The ball is recycled and the chance seems to be gone when Aaron Wainwright's pass goes to ground.
But the Dragons forwards recycle the ball and keep pounding at the Scarlets' line and their reward is a penalty for offside.
Sam Davies takes it from the left-hand side and another excellent connection from his left boot extends the Dragons' lead.
Dragons 6-3 Scarlets
A trademark burst from Scarlets' Wales scrum-half Gareth Davies, who sprints into the Dragons' 22 and bulldozes his way past opposition wing Ashton Hewitt.
But yet again it's a handling error which stalls progress from the Scarlets' next phase. Dragons have a scrum a little in front of their own 22.
Dragons 6-3 Scarlets
Nick Webb
BBC Wales Sport
It's all at arms length this handbags, of course no one ever throws a punch any more in this era of TV cameras.
Dragons 6-3 Scarlets
Here we go! A first scuffle of the match.
"Just a bit of pushing and shoving," referee Ben Whitehouse says - but he's still given Dragons a penalty because he says Scarlets Gareth Davies started the whole fracas.
Dragons kick into touch around 15 yards short of the halfway line.
Dragons 6-3 Scarlets
Handling errors all over the place so far in these opening 10 minutes.
You can see why - the rain is really driving down at Rodney Parade.
Dragons 6-3 Scarlets
Scarlets concede another penalty in kickable range, and this time it's Wales lock Jake Ball who's been penalised for being offside.
Dragons fly-half Sam Davies punishes Ball with a fine kick from a little to the left of the posts and the hosts are in front.
Adrian Hadley
Former Wales international on BBC Radio Wales
It's quite the crowd here at Rodney Parade. I didn't think we would get it with the weather as bad as it is, but they've turned out for this derby.
Adrian Hadley
Former Wales international on BBC Radio Wales
It was good play from the Scarlets, patient through the phases. Crashing up through Hadleigh Parkes and then running a few phases. The forwards weren't really getting anywhere and it's a penalty there for Elliot Dee not rolling away.
Dragons 3-3 Scarlets
Busy old start to this game!
Scarlets' Wales flanker Aaron Shingler goes off his feet at a ruck, giving his opponents a golden opportunity to equalise.
Sam Davies duly takes that chance with a simple kick through the posts and Dragons are level.
Dragons 0-3 Scarlets
And breathe...
After that frenetic start, Scarlets have a penalty after Dragons players do not move away from a tackle.
Leigh Halfpenny takes the penalty, right in front of the posts, and he strokes it over with ease to put the visitors in front.
Dragons 0-0 Scarlets
Scarlets do not get the early try after a review.
TMO Ian Davies deems full-back Leigh Halfpenny to have grounded the ball too early, without control of it over the Dragons' try line.
A let-off for the hosts and their scrum-half Rhodri Williams, who spilled the ball originally.
Dragons 0-0 Scarlets
Do we have a try already? Less than 30 seconds into the match?
Scarlets full-back Leigh Halfpenny pounces on a loose ball in the Dragons 22, kicked on by team-mate Gareth Davies.
Referee Ben Whitehouse is checking with the TMO but Halfpenny doesn't look confident...
Dragons 0-0 Scarlets
Referee Ben Whitehouse has blown his whistle and the first Welsh derby of the Pro14 festive schedule is under way!