Leinster made a host of changes having already secured top spot on the RaboDirect PRO12 table but had enough to see off the Dragons 22-18.
There wasn't much to play for at Rodney Parade with Leinster already guaranteed to finish at the summit after a stellar season and the Dragons destined to finish in the lower reaches of the league regardless of the result.
Nevertheless, the much-changed Leinster side seemed intent on maintaining the imperious run of form which has seen them lose just once in the league since September.
Ian Madigan got them off to a solid start by kicking three penalties to Lewis Robling's two in the opening twenty minutes before young prop Jack McGrath went over for the game's first try.
Despite the try, the match was struggling to get going really with the penalty count high for both sides and, after a missed shot at goal apiece from Robling and Madigan, the visitors had to settle for a 10-point lead at the interval with the score 6-16.
It didn't spring into life as a spectacle after the half-time break either but the leaders never looked like relinquishing their lead and, indeed, Madigan added his fourth and fifth penalties of the evening to stretch the advantage to 22-6.
The Dragons did run in two late tries through Dan Lydiate and replacement Jevon Groves though to record a losing bonus point which sees them finish the season in ninth place, just above Treviso on points difference.
The Leinster team that takes to the field in the play-offs will certainly look a lot different to today's line-up but they maintained their phenomenal winning run and are still on course to become the first side since Wasps in 2004 to do a domestic and European double.
Tries: Lydiate, Harries
Pens: Robling 2
Tries: J McGrath
Pens: Madigan 5
Dragons: 15 Hallam Amos, 14 Will Harries, 13 Adam Hughes, 12 Ashley Smith, 11 Aled Brew, 10 Lewis Robling, 9 Wayne Evans, 8 Toby Faletau, 7 Lewis Evans, 6 Danny Lydiate, 5 Rob Sidoli, 4 Luke Charteris (capt), 3 Nathan Buck, 2 Sam Parry, 1 Nathan Williams.
Replacements: 16 Steve Jones, 17 Phil Price, 18 Dan Way, 19 Jevon Groves, 20 Tom Brown, 21 Jonathan Evans, 22 Pat Leach, 23 Jack Dixon.
Leinster: 15 David Kearney, 14 Andrew Conway, 13 Brendan Macken, 12 Noel Reid, 11 Fionn Carr, 10 Ian Madigan, 9 Eoin Reddan, 8 Leo Auva'a, 7 Dominic Ryan, 6 Kevin McLaughlin (capt), 5 Damian Browne, 4 Devin Toner, 3 Nathan White, 2 Sean Cronin, 1 Jack McGrath.
Replacements: 16 Aaron Dundon, 17 Heinke van der Merwe, 18 Jamie Hagan, 19 Mark Flanagan, 20 Jordi Murphy, 21 Luke McGrath, 22 Isa Nacewa, 23 Darren Hudson.
Referee: Marius Mitrea