Leinster's pack proved too strong for Scarlets as the Irish province dominated up front to claim their fourth win of the season.

Johnny McNicholl gave Scarlets an early lead but the visitors were 21 points down by the time they scored again through debutant Tomas Lezana, after Caelan Doris grabbed Leinster's fourth.

With last season's Pro14 champions close to full strength it was always going to be a tough ask for Scarlets coming off the back of a heavy defeat by Munster last weekend.

The Welsh side started brightly and were good value for their lead when it arrived in the 18th minute after quick hands from Johnny Williams and Ioan Nicholas sent McNicholl in.

Leinster, as they had been a week ago against Zebre, were sloppy in the game's opening quarter but with 13 Ireland internationals in their starting side, they were always likely to eventually offer a response to Scarlets' good start.

After Hugo Keenan's effort was chalked off for a lack of downward pressure in his grounding, the hosts crossed the whitewash through hooker Kelleher at the back of a maul.

The try saw Leinster click into gear and suddenly their pack began to control proceedings. They had a second score just five minutes later through Porter whose pick-and-go did the job after Jamison Gibson-Park was held up just short.

With the mismatch in the pack becoming increasingly evident, Leinster opted to keep the ball in the forwards as half-time approached, and the inevitable try was eventually awarded by referee Marius van der Westhuizen for repeated Scarlets infringements.

It has been a tough start to life as Scarlets head coach from Dwayne Peel, whose side have now endured consecutive heavy defeats by Irish opposition. However there were some bright moments from his team - and the sight of Argentine debutant Lezana crossing the try-line having been put in by a wonderful Nicholas inside ball will have offered some relief on an otherwise difficult evening in Dublin.

Having earlier secured the bonus point through Caelan Doris, Leinster's replacement front rows picked up where the starters had left off with Irish centurion Cian Healy charging over before a late pair from Dan Sheehan brought the province over 50 points with McNicholl in the sin-bin for not rolling away.

Leinster: Hugo Keenan; Jordan Larmour, Garry Ringrose, Ciaran Frawley, James Lowe; Johnny Sexton (capt), Jamison Gibson-Park; Andrew Porter, Ronan Kelleher, Tadhg Furlong, Ross Molony, James Ryan, Caelan Doris, Josh van der Flier, Jack Conan.

Replacements: Dan Sheehan, Cian Healy, Michael Ala'alatoa, Ryan Baird, Rhys Ruddock, Luke McGrath, Ross Byrne, Jimmy O'Brien.

Scarlets: Ioan Nicholas; Johnny McNicholl, Jonathan Davies (capt), Johnny Williams, Ryan Conbeer; Sam Costelow, Gareth Davies; Wyn Jones, Ken Owens, WillGriff John, Lloyd Ashley, Sam Lousi, Aaron Shingler, Tomas Lezana, Blade Thomson

Replacements: Ryan Elias, Rob Evans, Samson Lee, Morgan Jones, Shaun Evans, Kieran Hardy, Dan Jones, Tom Rogers.

Referee: Marius van der Westhuizen (SARU)

Assistant referees: Stuart Gaffikin & Shane Kierans (IRFU)

TMO: Paul Larter (SRU)

Late Barron try gives Munster win over Connacht

Diarmuid Barron's 79th minute try preserved Munster's undefeated record in the United Rugby Championship as they edged past Connacht in the first interpro of the season.

Barron drove over after a period of sustained pressure allowing Joey Carbery to kick the conversion with just a minute remaining.

Munster had been far from their best against a dogged Connacht, who produced a far better showing than they did in their defeat by Dragons a week ago.

Chris Cloete touched down from Tadhg Beirne's kick through on the stroke of half-time to give Munster lead they scarcely deserved after a limp opening 40 minutes.

The score appeared to settle the hosts going into the second half, with Carbery landing a pair of penalties to stretch their lead to seven points.

Paul Boyle's quick tap-and-go saw Connacht claw the deficit back to just two points. With the hosts holding onto a narrow lead they looked to see the game out, but Carbery saw his kick charged down by opposite number Carty who collected and ran underneath the posts to put his side ahead.

Munster applied pressure near the Connacht line, using their forwards to barrel towards the line with multiple pick-and-goes before space emerged allowing Barron to run in.

The result means while Munster remain undefeated, they were not able to recapture top spot from Ulster, who are now the only side to have collected maximum points from the opening four games of the season.

Each side will play a fifth game next week before the league pauses for a month during the autumn internationals.