With fifteen points from their five games played, this bonus point win keeps them in touch with the early pace-setters, who, unlike Phil Davies’s side, did not secure a bonus point in Ireland.

The Blues did beat Munster 17-19, but it was in no way as impressive a performance as that given by the Scarlets. They scored six tries in what can best be described as a routing of Leinster, who, even without the majority of their Ireland World Cup players, are an accomplished side.

Jon Edwards, twice, James Bater and Regan King all crossed in a 10-minute spell that belied a tight first period, with Morgan Stoddart also scoring late.

The Welsh had led just 16-11 at the break through a Matthew Watkins try and the boot of fly half Rhys Priestland. Leinster claimed tries from Christian Warner, Stan Wright and Jamie Heaslip but still fell far short.

Watkins gave the Scarlets a perfect start as the wing raced over after three minutes, courtesy of a flowing move down the left and an inside pass from King. Priestland added the extras, but Leinster replied within 60 seconds as Warner took advantage of some poor tackling to barge through for an unconverted try.

The Welsh side to lead 16-11 on 32 minutes after a penalty kick swapping session between the impressive Priestland and his opposite number Jonathan Sexton. And in the second period the Scarlets seemed to find another gear which Leinster could not live with.

First Bater sold Rob Kearney an outrageous dummy to go under the posts for a seven-pointer. Then a clean break from Garan Evans seemed to have sent Edwards to the line, only for a handful of blue shirts to get back to haul the back row down just short.

Three more tries then followed in a five-minute burst as Leinster's defence was ripped to pieces. Edwards, outstanding in his support play, was on hand to claim two of them, book-ending one under the posts from King that secured a bonus point after a fine run by Stoddart.

In amongst that turmoil, Leinster flanker Shane Jennings was sent to the sin-bin after venting his frustration at the referee with an ill-judged expletive.

Scarlets back row Bater then saw yellow and the Leinster pack enough edge to shunt replacement prop Wright over. Forward power again paid dividends for the home side as Heaslip carried over from the base of a scrum. The sniff of a bonus point for a fourth try gave Leinster extra urgency.

But instead the Scarlets had the last word as fullback Stoddart went over late on for the Welsh side's sixth try.

Leinster 23 (11)
Tries: Warner, Wright, Heaslip
Cons: Sexton
Pens: Sexton (2)

Scarlets 52 (16)
Tries: Watkins, Bater, Edwards (2), King, Stoddart
Cons: Priestland (5)
Pens: Priestland (4)