Leinster’s greater strength in depth helped them complete a festive derby double at the Sportsground as they got the better of a youthful Connacht side…
Following up on their 19-6 Dublin defeat of Ulster a week ago, Matt O'Connor's men came good in the second half in Galway thanks to two Jimmy Gopperth penalties and a 73rd minute converted try from Gordon D'Arcy.
Fionn Carr's second try in three league games had Connacht 8-3 ahead at the break, with Ian Madigan and Jack Carty exchanging penalties.
But with their bench having an impact, the visitors hit the front for the first time in the 63rd minute and replacement Gopperth set up D'Arcy's first try since last April.
The result keeps Leinster in second place in the RaboDirect PRO12 table, with the gap between the defending champions and table-topping Munster now just three points.
Pat Lam handed 21-year-old out-half Carty his first start, and Darragh Leader and Kieran Marmion also featured in a Connacht back-line that had an average age of just 22.
A pinpoint early touchfinder settled Carty's nerves, but Connacht failed to capitalise on an initial bout of pressure as both sides probed with the boot.
Jason Harris-Wright was isolated for a 13th minute ruck penalty which Madigan sent narrowly wide and the stalemate ensued for another nine minutes.
It took a brilliant break over halfway from Robbie Henshaw to light up proceedings. With Brian O'Driscoll shooting up out of defence, Henshaw did well to evade Dave Kearney's grasp before passing wide for former Leinster winger Carr to charge over in the right corner past Madigan's covering tackle.
Carty was unable to convert and full-back Leader missed two long range penalty efforts in quick succession, while the crossbar denied Madigan on the half hour mark.
In a game of few line-breaks, ex-Connacht hooker Sean Cronin got Leinster on the front foot before an Andrew Browne infringement allowed Madigan to open the visitors' account at the third attempt.
But Connacht responded on the stroke of half-time, Matt Healy and Browne gaining good ground on the left and Carty rewarded them by finding the posts from a subsequent penalty.
Connacht maintained their lead during the early stages of a rain-hit second period, with Leinster having to bide their time.
Gopperth, who came on as part of a trio of replacements, cut the gap to 8-6 with his first penalty attempt in the 57th minute.
The New Zealander added another six minutes later following a Jamie Heaslip charge from a scrum.
A late tackle by the Leinster captain on Parks then led to a kickable penalty at the other end, but the latter missed the target on the near right side.
Heaslip and back row colleague Jordi Murphy, who picked up his second successive man-of-the-match award, were central to a strong spell of carrying that preceded D'Arcy's decisive try.
Leinster built from a lineout maul on the left and Heaslip, Devin Toner, Murphy and Dominic Ryan all took the ball on before Gopperth slipped a pass away for the supporting D'Arcy to nip in behind the posts.
Connacht felt the final pass was forward but television match official Jude Quinn ruled otherwise, and Gopperth's simple conversion closed out a satisfying finish for Leinster.
CONNACHT SCORERS: F. Carr (1 try), J. Carty (1 penalty)
LEINSTER SCORERS: G. D'Arcy (1 try), J. Gopperth (1 conversion and 2 penalties), I. Madigan (1 penalty)
CONNACHT: D Leader; F Carr, R Henshaw, E Griffin, M Healy; J Carty, K Marmion; B Wilkinson, J Harris-Wright, N White, M Kearney, C Clarke CAPTAIN, A Browne, J Muldoon, E McKeon.
REPLACEMENTS: D Heffernan, D Buckley, R Ah You, M Swift, G Naoupu, P O'Donohoe, D Parks, T O'Halloran.
15: Rob Kearney
14: Zane Kirchner
13: Brian O'Driscoll
12: Gordon D'Arcy
11: Dave Kearney
10: Ian Madigan (Jimmy Gopperth, 54)
9: Eoin Reddan (Isaac Boss, 54)
1: Jack McGrath (Jack O'Connell, 76)
2: Sean Cronin (Aaron Dundon, 70-76)
3: Martin Moore (Mike Ross, 47)
4: Devin Toner
5: Tom Denton (Mike McCarthy, half-time)
6: Rhys Ruddock (Dominic Ryan, 54)
7: Jordi Murphy
8: Jamie Heaslip CAPTAIN
REPLACEMENT NOT USED: Brendan Macken.
REFEREE: George Clancy (IRFU), ASSISTANT REFEREES: Leo Colgan, Olly Hodges (both IRFU), CITING COMMISSIONER: Denis Templeton (IRFU), TMO: Jude Quinn (IRFU).