LEINSTER 13 NORTHAMPTON SAINTS 21, Donnybrook
Scorers: Leinster: Tries: Martin Moore, Dan Leavy; Pen: Jimmy Gopperth
Northampton Saints: Tries: Gareth Denman, Samu Manoa; Con: Stephen Myler; Pens: Stephen Myler, Sam Olver 2
Playing in their final pre-season encounter before their new RaboDirect PRO12 campaign begins in earnest next weekend, Leinster started with plenty of intent.
After a promising sequence of play in the Northampton 22, Matt O'Connor's men took the lead with just five minutes on the clock.
Lansdowne prop Martin Moore supplied the finishing touches on this occasion, as he drove over at the end of a powerful maul to the right of the Northampton posts.
This was precisely the start that O'Connor would have been hoping for in front of a lively home crowd, and although out-half Jimmy Gopperth was marginally wide with his conversion from a tight angle, they had developed a positive early platform.
Northampton, who had British & Irish Lions George North and Alex Corbisiero in their starting line-up, soon settled into the proceedings though.
Saints were back on terms 18 minutes into the contest when their own tighthead prop, Gareth Denman, stylishly finished off an enterprising drive from a wide position.
Place-kicker Stephen Myler's conversion attempt drifted past the target from the left wing, however, and Leinster took full advantage of this missed opportunity just four minutes later.
Gopperth - playing in his second game since his summer move from Newcastle Falcons and linking well with confident young scrum half Luke McGrath - coolly slotted a routine penalty between the posts.
This ensured that Leinster took an encouraging 8-5 lead into the second period, but with the two sides opting to utilise their replacement benches to a major extent, play did start to open up as the game wore on.
Samu Manoa stormed over on the left hand side ten minutes after the restart for Saints' second try. With Myler following his expertly-taken conversion with a comfortable 58th minute penalty, Leinster now found themselves 15-8 down.
Northampton were starting to dominate territorially heading into the final quarter, and they extended their advantage even further 14 minutes from time courtesy of a clinically struck penalty by replacement Sam Olver.
During the closing stages, Northampton used their greater on-field experience to their advantage and opened up an insurmountable cushion four minutes from the end with another Olver three-pointer from distance.
O'Connor's young home side managed to increase the tempo late on, aided by half-time replacements Eoin Reddan and David Kearney who made welcome returns in the back-line.
Promising flanker Dan Leavy, who came on for captain Shane Jennings, broke through for a well-deserved 79th minute try but it was not enough to deny Northampton a hard-earned victory.
LEINSTER: Darren Hudson; Darragh Fanning, Brendan Macken, Noel Reid, Sam Coghlan Murray; Jimmy Gopperth, Luke McGrath; Jack McGrath, Aaron Dundon, Martin Moore, Quinn Roux, Tom Denton, Rhys Ruddock, Shane Jennings (capt), Jordi Murphy.
Replacements used: David Kearney for Hudson, Eoin Reddan for L McGrath, Sean Cronin for Dundon, Ben Marshall for Denton, Leo Auva'a for Ruddock (all half-time), Colm O'Shea for Macken (49 mins), Hudson for Fanning, Jack O'Connell for J McGrath, Thomas Daly for Reid, Dominic Ryan for Murphy (all 52), Dan Leavy for Jennings (57), Cathal Marsh for Gopperth, Tadhg Furlong for Moore (both 63), Adam Byrne for Coghlan Murray, Tadhg Beirne for Roux (both 67), James Tracy for Cronin (77). Not used: John Cooney, Fergus McFadden.
NORTHAMPTON SAINTS: James Wilson; Ken Pisi, George Pisi, Luther Burrell, George North; Stephen Myler, Lee Dickson; Alex Corbisiero, Ross McMillan, Gareth Denman, Courtney Lawes, Samu Manoa, Calum Clark, Phil Dowson (capt), Sam Dickinson.
Replacements: Alex Waller, Mike Haywood, Tom Mercey, James Craig, Christian Day, Tom Wood, Ben Nutley, GJ Van Velze, Ryan Glynn, Sam Olver, Jamie Elliott, Tom Stephenson, Paul Diggin, Tom Collins, Vasily Artemyev.
Referee: George Clancy (IRFU)