Before Saturday's trip to Stradey Park, Leinster had won just twice in their last ten matches on Welsh soil - Llanelli ruthlessly continued that trend with a 33-21 battering of the province.
MAGNERS LEAGUE: Saturday, September 23
LLANELLI SCARLETS 33 LEINSTER 21, Stradey Park (Att: 6,721)
Scorers: Llanelli: Tries: Dafydd James 2, Regan King, Inoke Afeaki; Cons: Stephen Jones 2; Pens: Jones 3
Leinster: Tries: Denis Hickie 2, Trevor Hogan; Cons: Felipe Contepomi 3
Phil Davies' Llanelli outfit went back to the top of the Magners League table as they picked up their fourth win in five games and condemned Leinster to their second defeat in three outings.
Michael Cheika's men are already playing catch-up in the competion, sitting in tenth place and just a point ahead of Munster.
Missing a host of their Irish internationals, Leinster were left trailing in the hosts' wake on Saturday as, following a dropped kick-off by Stephen Keogh, former Lion Dafydd James scored the first of his two tries inside 70 seconds.
Backs and forwards combined to put Tongan lock Inoke Afeaki over for a score soon after, and New Zealand centre Regan King swapped passes with Ceiron Thomas to put James racing through for his second. A conversion and penalty from the boot of out-half Stephen Jones left Llanelli 20-0 in front with just 15 minutes on the clock.
Leinster simply had no answer to Llanelli's stylish play and their bonus point arrived just at the first quarter's end when King galloped through a non-existent Leinster defence to dot down and allow Jones to convert.
Ireland winger Denis Hickie did manage to save some face for the visitors - they went in 27-7 down at the break - as he managed to intercept a stray pass from Dwayne Peel and race 60 metres to the try line. Felipe Contepomi converted.
Leinster got the best possible start to the second half when they notched their second converted try through Hickie. The Dubliner plunged over under pressure from Peel, who was subsequently forced off with an arm injury.
That was Hickie's 24th try in the history of the Celtic League, drawing him level with former Dragons back row Jason Forster, the man currently at the top of the scoring charts.
Leinster's mini-revival continued as only some desperate defence from the Scarlets prevented the in-form Hickie from going in at the corner flag for his third.
Jones helped settle the Welsh side back down with a 58th-minute penalty for 30-14. But Leinster clawed their way back to within nine points when a quick tap from replacement scrum half Chris Whitaker allowed former Munster lock Trevor Hogan to barge his way through and in under the posts. Contepomi made it a seven-pointer.
Well and good as Leinster's fight back was, a malfunctioning lineout left them without a plentiful supply of possession and full-back Thomas' booming touch finders kept the Scarlets on the move.
Llanelli shut up shop for the closing quarter-hour with their defence water-tight and Jones' third penalty of the evening sealed the win.
Llanelli: Ceiron Thomas; Mark Jones, Matthew Watkins, Regan King, Dafydd James; Stephen Jones, Dwayne Peel; Iestyn Thomas, Matthew Rees, Craig Dunlea, Inoke Afeaki, Scott Macleod, Simon Easterby (capt), Gavin Thomas, Alix Popham.
Replacements used: Deacon Manu for Dunlea, Adam Jones for Afeaki (half-time), Clive Stuart-Smith for Peel (46 mins), Barry Davies for King (68), Gavin Evans for Watkins (70), James Bater for G Thomas (78), Ken Owens for Rees (80).
Leinster: Robert Kearney; Luke Fitzgerald, Kieran Lewis, Michael Berne, Denis Hickie; Felipe Contepomi (capt), Guy Easterby; Ronan McCormack, Harry Vermaas, Will Green, Trevor Hogan, Owen Finegan, Stephen Keogh, Keith Gleeson, Jamie Heaslip.
Replacements used: Gary Brown for Kearney (10 mins), Chris Whitaker for Easterby (24), Bernard Jackman for Vermaas (half-time), Adam Byrnes for Hogan, Niall Ronan for Keogh (both 74), Christian Warner for Fitzgerald (80). Not used: Reggie Corrigan.
Referee: David Changleng (Scotland)
Touch Judges: Hugh Watkins, Matthew Aplin (both Wales)