Defending champions Leinster delivered a masterclass at Parc y Scarlets to overwhelm the home side 52-25 in a rearranged Guinness PRO14 clash.

The Irish province crossed for seven converted tries to post their biggest ever points tally in Llanelli.

Scarlets crossed for three tries through scrum-half Dane Blacker and replacement half-backs Will Homer and Angus O’Brien, but were on the back foot for most of the match.

Both sides showed plenty of changes from their previous PRO14 outings and it was Scarlets who were first on the scoreboard after just two minutes thanks to a penalty from 20-year-old fly-half Sam Costelow, making his first start in the competition.

Leinster, though, started growing into the contest and after a concerted period of pressure on the home line, Ireland international flanker Dan Leavy powered over for a score converted by fly-half Harry Byrne.

The response from the home side was swift and impressive.

No. 8 Uzair Cassiem, on his 50th Scarlets appearance, burst through the middle and the Springbok then timed his pass to perfection to send Blacker over wide out.

Costelow converted, but the lead didn’t last long as Leinster claimed their second try rom a powerful line-out drive with hooker James Tracy emerging from the pile of bodies with the ball.

Byrne and Costelow swapped penalties and the game appeared in the balance at 17-13, but with the Scarlets guilty of ill-discipline at crucial times, the end of the half belonged to Leinster with a penalty try - which led to Cassiem being shown yellow - and another by wing Cian Kelleher putting them in a commanding 31-13 lead at the interval.

Scarlets needed an immediate response after the restart, but instead it was the Irish side who added to their advantage through skipper Luke McGrath.

Scarlets did claim their second try on 64 minutes when Tyler Morgan raced clear before sending Homer on a free run to the line, but full-back Max O’Reilly stepped over and replacement David Hawkshaw added another to highlight Leinster’s ruthless nature.

There was time for a late solo score from O’Brien to raise hope for a potential try bonus point, but Scarlets were unable to find any further way through.