|Pro12 Judgement Day|
|Newport Gwent Dragons (13) 20|
|Tries: Warren, Hughes Cons: O'Brien 2 Pens: O'Brien 2|
|Scarlets (20) 34|
|Tries: S Williams, S Shingler, S Evans, G Davies Cons: S Shingler 4 Pens: S Shingler|
Scarlets clinched European Champions Cup qualification with a scrappy Pro12 bonus-point win over Newport Gwent Dragons on Judgement Day.
But they must win at Munster next Saturday and hope Ulster cannot beat Ospreys to clinch a play-off place.
Scott Williams marked his return from injury with a try while Steven Shingler, Steffan Evans and Gareth Davies also crossed.
Adam Warren and Adam Hughes crossed for the Dragons.
The west Wales region are only a point behind fourth-placed Ulster with one round of fixtures left.
The match did not live up to the Ospreys' 40-27 win over Cardiff Blues in the first of the double-header games. But the six tries meant the record Principality Stadium crowd of 68,262 for the event's fourth edition enjoyed 14 touchdowns.
Scarlets were 14-0 ahead in as many minutes, with Williams crossing after a break by Michael Collins and Shingler taking advantage of slack defending to dive over between the posts.
The Dragons, with nothing but pride to lay for, looked off the pace until Warren scored after Rynard Landman charged down a Shingler kick.
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From then until half-time it was a kicking contest between O'Brien and Shingler, with a yellow card for Scarlets prop Peter Edwards to provide a little variety as it led to uncontested scrums with Samson Lee injured.
It took Scarlets five minutes after the restart to stretch their lead through Evans, though Hughes' sharp finish kept Dragons within one score.
Replacement scrum-half Gareth Davies underlined his try-scoring reputation when he claimed the bonus point score six minutes from the end, with Shingler's conversion giving him a 19-point haul.
On a day when Wales captain Sam Warburton suffered a shoulder injury, national coach Warren Gatland will have further worries after Scarlets tight-head Lee's blow to the head.
Dragons: Carl Meyer, Adam Hughes, Adam Warren, Jack Dixon, Hallam Amos, Angus O'Brien, Charlie Davies; Phil Price, Elliot Dee, Brok Harris, Rynard Landman, Nick Crosswell, Lewis Evans (capt), Nic Cudd, Taulupe Faletau.
Replacements: Rhys Buckley, Luke Garrett. Lloyd Fairbrother, Matthew Screech, Ed Jackson, Sarel Pretorius, Dorian Jones, Geraint Rhys Jones.
Scarlets: Michael Collins; Liam Williams, Hadleigh Parkes, Scott Williams, Steff Evans; Steven Shingler, Aled Davies, Rob Evans, Ken Owens (capt), Samson Lee, Jake Ball, David Bulbring, Lewis Rawlins, James Davies, John Barclay.
Replacements: Ryan Elias, Dylan Evans, Peter Edwards, Jack Condy, Morgan Allen, Gareth Davies, Aled Thomas, Gareth Owen
Referee: Ben Whitehouse (WRU)
Assistant referees: Gwyn Morris, Wayne Davies (both WRU)
Citing commissioner: Gwyn Bowden (WRU)
TMO: Gareth Simmonds (WRU)