Scarlets suffered their first defeat of the PRO12 season when they went down 19-15 to Leinster at the RDS on Friday.
Tries from centres Hadleigh Parkes and Gareth Owen helped give the Welsh region a 15-9 advantage at the interval.
Ian Madigan kicked three penalties for the Irish province before the break to keep them in contention and they went ahead in the second period through Mike Ross' converted touchdown. Madigan then added another from the tee as Leinster secured a deserved victory.
Leo Cullen named a number of his Ireland internationals in the team to face the
They controlled possession and, after a period of pressure close to the hosts' line, the burly Parkes barged over from close range.
Leinster did hit back, putting together a lengthy drive which resulted in Jake Ball being sin-binned, but a penalty from Madigan was all they could accrue while the lock was off the field.
After Ball returned, the Dublin-based outfit's fly-half added his second from the tee before the Scarlets crossed the whitewash again through Gareth Owen.
Although Madigan kicked another three-pointer to reduce the arrears, it proved to be brief as Dan Jones was also successful with the boot as Wayne Pivac's team went into the break 15-9 ahead.
The Irish side were second best in the first half but they opened the final 40 minutes on the front foot and Ross' score was the reward for their endeavour.
Leinster were now firmly on top and a penalty from Madigan gave the Irish province a four-point buffer with a quarter of the match remaining.
Scarlets went close to scoring with the last move of the encounter, but the hosts held on for the win.
Pens: Madigan 4
Tries: Parkes, Owen
Yellow card: Ball
Leinster: 15 Rob Kearney, 14 Zane Kirchner, 13 Garry Ringrose, 12 Noel Reid, 11 Cian Kelleher, 10 Ian Madigan, 9 Isaac Boss, 8 Jamie Heaslip (c), 7 Sean O'Brien, 6 Dominic Ryan, 5 Tom Denton, 4 Devin Toner, 3 Mike Ross, 2 James Tracy, 1 Cian Healy.
Replacements: 16 Bryan Byrne, 17 Jack McGrath, 18 Marty Moore, 19 Hayden Triggs, 20 Dan Leavy, 21 Luke McGrath, 22 Johnny Sexton, 23 Ben Te'o.
Scarlets: 15 Aled Thomas, 14 Tom Williams, 13 Gareth Owen, 12 Hadleigh Parkes, 11 Michael Tagicakibau, 10 Dan Jones, 9 Gareth Davies, 8 John Barclay (c), 7 James Davies, 6 Aaron Shingler, 5 Lewis Rawlins, 4 Jake Ball, 3 Peter Edwards, 2 Emyr Phillips, 1 Rob Evans.
Replacements: 16 Ken Owens, 17 Dylan Evans, 18 Will Taylor, 19 Tom Price, 20 Maselino Paulino, 21 Aled Davies, 22 Michael Collins, 23 Harry Robinson.
Venue: RDS Arena
Referee: Leighton Hodges (Wales)
Assistant referees: Leo Colgan (Ireland), Olly Hodges (Ireland)
TMO: Seamus Flannery (Ireland)