Ian Madigan kicked a penalty in either half to secure a 6-0 victory over the Glasgow Warriors in a dreadful match.
In a dull and dour first period, the only points before the interval came through the boot of Madigan as the Irish province led 3-0. The fly-half then added another after the break to seal the win and take the Irish team into the play-off places.
Despite being without their established players, with 11 of them away on international duty, Leinster started the brighter. Madigan put the visitors ahead with a penalty and they continued to press throughout the opening quarter.
A yellow card for Tom Ryder piled further pressure on the hosts, but the Irish province struggled to take the opportunities that presented themselves.
Glasgow's scramble defence was excellent and they rode out the period with Ryder off the field. But both sides were finding it difficult to hold on to the ball and the half ended with Leinster narrowly in the lead.
The match continued in the same vein in the second period with the three-time Heineken Cup champions controlling proceedings.
Chris Fusaro became the second Warriors' player to be sin-binned as they once again succumbed to their own ill-discipline. And Madigan made no mistake from the resultant chance to extend the visitors' advantage to 6-0 with 30 minutes remaining.
The hosts finally found a foothold in the match but opportunities went begging as Pete Horne and Scott Wight both missed from the tee, and that ended their hopes of a comeback.
Pens: Madigan 2
Glasgow: 15 Peter Murchie, 14 Tommy Seymour, 13 Alex Dunbar, 12 Peter Horne, 11 DTH Van Der Merwe, 10 Ruaridh Jackson, 9 Sean Kennedy, 8 Josh Strauss, 7 Chris Fusaro (c), 6 Rob Harley, 5 Tom Ryder, 4 Tim Swinson, 3 Mike Cusack, 2 Pat MacArthur, 1 Gordon Reid.
Replacements: 16 Finlay Gillies, 17 Ofa Fainga'anuku, 18 Moray Low, 19 James Eddie, 20 Ryan Wilson, 21 George Graham, 22 Scott Wight, 23 Byron McGuigan.
Leinster: 15 Isa Nacewa, 14 Dave Kearney, 13 Brendan Macken, 12 Andrew Goodman, 11 Fionn Carr, 10 Ian Madigan, 9 Isaac Boss, 8 Sean O'Brien, 7 Shane Jennings,6 Kevin McLaughlin,5 Quinn Roux, 4 Leo Cullen, 3 Jamie Hagan, 2 Aaron Dundon, 1 Jack McGrath.
Replacements: 16 Thomas Sexton, 17 Jack O'Connell, 18 Martin Moore, 19 Devin Toner, 20 Jordi Murphy, 21 John Cooney, 22 Noel Reid, 23 Andrew Conway.
Referee: Neil Hennessy (Wales)