Scarlets kept in touch with the top four places as they got the better of the Dragons on Saturday, winning 34-20 at the Principality Stadium.
First half tries from Scott Williams and Steve Shingler helped the away side to the victory, before Steffan Evans and Gareth Davies added to them in the second half.
Dragons scored tries of their own through Adam Warren and Adam Hughes, but were unable to do enough to overcome Scarlets.
An early try from Scarlets' Williams opened the scoring as he ran home unchallenged after eight minutes, allowing Shingler to open his account from the tee.
Shortly after Shingler scored a try of his own, as he battled through the Dragons' defence to score under the posts before adding the extras.
Dragons hit back through Warren ten minutes later, as Rynard Landman charged down Shingler's clearance, before the outside centre capitalised on poor handling from the Scarlets defence to slide over. Angus O'Brien slotted the conversion.
A quick exchange of kicks saw O'Brien and Shingler take it in turns to add penalties, with both fly-halves slotting twice each in quick succession before the break.
Evans ran home Scarlets' third try of the afternoon after being set clear by Hadleigh Parkes, before Shingler's conversion took the score to 27-13 in favour of the visitors.
Late in the second half full-back Carl Meyer claimed a Shingler clearance, before making up plenty of ground and shipping the ball wide to Hughes to finish the move off as he crashed over the try line. O'Brien slotted a superb conversion from wide on the right to bring Dragons within a converted try of Scarlets.
Some quick thinking from Scarlets scrum-half Davies saw him burst through a gap in the Dragons' defence and seal the bonus point, before Shingler added the conversion.
The victory for Scarlets means a play-off spot is not out of the reckoning, but with Ulster winning earlier in the day other results will have to go their way in the final round of fixtures.
Tries: Warren, Hughes
Cons: O'Brien 2
Pens: O'Brien 2
Tries: S Williams, Shingler, Evans, G Davies
Cons: Shingler 4
Pens: Shingler 2
Dragons: 15 Carl Meyer, 14 Adam Hughes, 13 Adam Warren, 12 Jack Dixon, 11 Hallam Amos, 10 Angus O'Brien, 9 Charlie Davies, 8 Taulupe Faletau 7 Nic Cudd, 6 Lewis Evans (c), 5 Nick Crosswell, 4 Rynard Landman, 3 Brok Harris, 2 Elliot Dee, 1 Phil Price
Replacements: 16 Rhys Buckley, 17 Luke Garrett, 18 Lloyd Fairbrother, 19 Matthew Screech, 20 Ed Jackson, 21 Sarel Pretorius, 22 Dorian Jones, 23 Geraint Rhys Jones
Scarlets: 15 Michael Collins, 14 Liam Williams, 13 Hadleigh Parkes, 12 Scott Williams, 11 Steff Evans, 10 Steven Shingler, 9 Aled Davies, 8 John Barclay 7 James Davies, 6 Lewis Rawlins, 5 David Bulbring, 4 Jake Ball, 3 Samson Lee, 2 Ken Owens (c), 1 Rob Evans
Replacements: 16 Ryan Elias, 17 Dylan Evans, 18 Peter Edwards, 19 Jack Condy,20 Morgan Allen, 21 Gareth Davies, 22 Aled Thomas, 23 Gareth Owen
Referee: Ben Whitehouse (Wales)
Assistant Referees: Gwyn Morris (Wales), Wayne Davies (Wales)
TMO: Gareth Simmonds (Wales)