The Welsh region scored tries either side of the interval from Martin Roberts and Deacon Manu. But Leinster captain Shane Jennings struck on the hour mark and 16 points from Felipe Contepomi clinched victory at Parc y Scarlets.
The hosts sat in fourth position in the title race but were without four of their Wales contigent for the clash at Parc y Scarlets while Gordon D’Arcy lined up at centre for the visitors aiming to impress Ireland coach Declan Kidney and stake a claim for next Saturday’s Six Nations clash against England at Croke Park.
D’Arcy and his team-mates got off to the best possible start through two quick-fire Contepomi penalties inside the opening 12 minutes.
Leinster were in confident mood and scored the opening try at the end of the opening quarter when Rocky Elsom cut through before D’Arcy and Girvan Dempsey combined to send Isa Nacewa over.
Michael Cheika’s men doubled their advantage six minutes later when Priestland’s kick was charged down by Dempsey and flanker Jowitt pounced for the second try.
Rhys Priestland finally got the Scarlets on the scoreboard with a penalty on the half hour mark before Martin Roberts evaded Stan Wright’s tackle to score a converted try.
Contepomi added another penalty but the Scarlets rallied after the break when prop Deacon Manu fended off Trevor Horgan’s weak tackle to crash over for the hosts’ second try and Priestland’s conversion put the Scarlets within a score of the lead.
But Leinster responded in style when Jennings added a third on the hour mark and despite Contepomi’s yellow card for a professional foul, the champions held on for a comfortable win.
