Ulster conceded four tries in the first half but managed to outscore the visitors in the second period.
It took Leinster just two minutes to opening the scoring.
After Ulster knocked on in a promising position Leinster secured their own ball at the scrum, No8 Luke Fagan’s powerful run put a dent in the home defence, the ball was moved quickly through the hands, blindside flanker Joshua Chukwuemeka burst into the Ulster 22.
The ball was moved from east to west, hooker Hugh Greany drew the last defenders before popping the ball to openside flanker Mike Brangan to power over but centre Daragh Farrell to convert.
Leinster breached the Ulster defence again six minutes later, the home side had a lineout in their own 22, hooker Adam Caldwell overthrew the ball allowing opposition tighthead Evan Shelley to pick up and barge over from close range with Farrell landing the conversion.
Leinster’s impressive pack paved the way for their third try on 13 minutes, they patiently work the ball through a number of phases close to the Ulster line before spinning it in field for Farrell to stretch over and dot down, and the Leinster captained converted his own score.
Ulster opened their account on 25 minutes with their first sortie into the Leinster 22.
The home side kicked a penalty to the corner, the forwards secured the lineout and set up a powerful driving maul with Caldwell being propelled over to touchdown, scrum half Chris McVicker added the conversion.
Leinster were denied a try five minutes later they kicked a penalty to touch, Branagan surged for the line, he was stopped short the ball was recycled as the visitor’s forwards surged for the line but Ulster were able to get enough bodies under the ball to prevent a grounding.
It was only temporary reprieve for Ulster, as from the goal line drop out Leinster ran the ball moving through the hands to create space for Fagan to dart over in the corner.
Farrell converted from a tight angle to give Leinster a 26-7 half time lead.
Caldwell crossed for his second try four minutes after the restart and it was a carbon copy of his first, Ulster kicked a penalty to touch, the pack set up a driving maul and the hooker dotted down but McVicker couldn’t convert.
Leinster scored their fifth try on 51 minutes, a poor kick out of Ulster’s defence was fielded by scrum half Stephen Hendy, he set off on a run beat the covering tackle before putting full back Cathal Kehoe over in the corner with Farrell adding the extras.
Leinster should have been over again on 55 minutes, from a defensive five metre lineout Ulster again missed their jumpers at the back, Leinster replacement Eion O’Doherty collected but knocked on ground the ball.
Ulster produced their best bit of rugby to score a third try on 70 minutes.
Replacement Sam McElroy broke from his own half and his jinking run took him deep into Leinster territory, the ball was quickly recycled, centre Tom Bell surged for the line but he was stopped replacement prop Toby Newman went over from close range with Danny Guy converting.
Teams
Ulster
(1-8) J Mark, A Caldwell, J Dobbin, O Hughes, N Bell, H McIlwaine, B Newell, R Hanna
(15-9) J Orr, R McDowell, T Bell, C Cummings, J Barron, O O’Kane, C McVicker
Replacements: K Brolly, T Newman, T McGilloway, D Fox, R Bell, D Guy, S McElroy, E Spratt, T Pitts, Z Holmes
Leinster
(1-8) C Gartland, H Greany, E Shelley, C Butler, S Walsh, J Chukwuemeka, M Branagan, L Fagan
(15-9) C Kehoe, C Mulligan, H Fagan Harold, D Farrell, O O’Hara, J Litchfield, S Hendry
Replacements: H Dunne, J King, C Scott, W Hook, E O’Doherty, P Gorman, D Norval