Centre Rory O'Loughlin's try in the final play supplemented Ciaran Frawley's 30th-minute penalty.

Turning into a swirling wind, Scarlets left points behind them before Kieran Hardy's converted score closed the gap to three points and then Dan Jones booted them level on the hour mark.

Those well-taken scores from wingers Lowe (68 minutes) and Daly (71) put Leinster back in control until Hardy completed his brace, setting up a nervy but scoreless final seven minutes.

Despite David Bulbring's early injury departure, there were positive early signs for Scarlets with scrum half Hardy and Ioan Nicholas both opening up the defence.

Kieron Fonotia fumbled in a promising situation, while a knock-on from captain Kearney halted Leinster's progress.

While the knock-ons and forward passes continued to blight play, Leinster built well until O'Loughlin was isolated by Dan Davis for a clearing penalty.

The hosts hit the front on the half-hour mark, prop McGrath barrelling through into the 22 before the prolonged attack ended with Frawley making it 3-0.

Jake Ball, the only one of Scarlets' 12 Wales call-ups on duty, consistently got over the gain-line but they were thwarted again when Marc Jones' neck roll on McGrath, right on the Leinster line, gave the home side a relieving penalty.

Indeed, Leinster showed their clinical edge late on with Lowe's well-weighted kick earning them a close-in lineout.

Scarlets coughed up a penalty and although they defended the next maul, Mick Kearney's loose pass was gobbled up by Conor O'Brien and turned into a try by his centre partner O'Loughlin who spun out of tackles from Johnny McNicholl and Phil Price to score.

Young fly-half Frawley added the extras, just to the left of the posts.

Having intercepted a Frawley pass just seconds after the restart, Paul Asquith blundered when losing control of the ball inches from the line with TMO Olly Hodges ruling the try out.

Jones also fluffed his lines from a penalty attempt but the visitors got on the scoresheet when Davis fended off Kearney near halfway, sprinted down the touchline and passed inside for Hardy to finish off.

Jones converted and punished a Caelan Doris high tackle with a levelling 59th-minute penalty, only for Leinster to pick off two crucial tries.

Jones was tackled into touch, giving the hosts key field position and a few phases later replacement Jamison Gibson-Park's pass sent his fellow New Zealander Lowe over in the left corner past Asquith.

Frawley then converted Daly's terrific try on the opposite flank, burly prop Vakh Abdaladze rampaging into the 22 from a Bryan Byrne pass before fellow replacement Noel Reid's inviting kick was dotted down by the inrushing Daly.

Despite McNicholl's swift break setting up Hardy for his second seven-pointer, Scarlets had to settle for a losing bonus point with Asquith's pass going to ground on a last-minute break.