Borders surrendered their chance of a Heineken Cup quarter-final place as they were demolished by the Scarlets at Netherdale, Llanelli outclassing them in every department to pocket the bonus point.
The Scarlets - fresh from their triumph over Northampton - settled quickest and pinned the Scots back with a series of multi-phased surges, but all too often they spoiled the good work by spilling the crucial final pass.
They broke the deadlock at last in the 18th minute through a questionable penalty by Stephen Jones, awarded against George Graham for a high tackle. Jones repeated the dose less than two minutes later when Semo Sititi was offside at a ruck, then completed his treble.
Llanelli kept up the heavy pressure and eventually broke through thanks to a charge by Scott Quinnell. The full-back, Barry Davies, still had five markers to beat from five yards out, but a combination of his own strength and the arriving forwards took him over.
Borders replied in positive fashion to keep their prospects alive with a brilliantly worked Gregor Townsend try on the stroke of the interval.
Gareth Morton added the conversion, only for Quinnell to snuff out the hosts with a trademark rolling maul touchdown just after the restart.
Any chance of a Borders fightback was ended when the visitors' scrum-half, Dwayne Peel, scuttled over under the crossbar after combining with the flanker Simon Easterby.
The Scarlets claimed the vital bonus point as Garan Evans slithered over in the corner in the wake of more great work by Quinnell. Davies rounded off the rout with a superb chip-and-chase effort.
Stephen Jones shrugged off his man-of-the-match display to divert the praise to his forwards. He insisted: "It was a tremendous team effort, but it was the big guys up front who laid the platform. They were outstanding. We are delighted with the result, but there is still a lot of rugby to be played, with two hard games against Agen and a trip to Northampton."
Borders: Try: Townsend. Conversion: Morton. Penalty: Morton. Llanelli: Tries: B Davies 2, Peel, S. Quinnell, Evans. Conversions: S Jones 2. Penalties: S Jones 4.
Borders: G Morton; N Walker, G Townsend, K Utterson (capt), C Moir; T Vili, C Cusiter; G Graham, R Ford, B Douglas, D Weir, S MacLeod, C Feather, S Sititi, D Kane. Substitutes: K Todd, M Landels, C Stewart, A Rennick, G Armstrong, J Stuart, C Murray.
Llanelli: B Davies; G Evans, M Taylor, M Watkins, S Finau; S Jones, D Peel; I Thomas, R McBryde, J Davies, V Cooper (capt), A Jones, D Jones, S Quinnell, S Easterby. Substitutes: P John, A Gravelle, I Boobyer, D Burn, G Bowen, T Selley, D Hodges.
Referee: R Maybank (England).Reuse content