Leinster 34-26 Ulster
Leinster (27) 34
- Tries: Strauss, Fitzgerald, Horgan 2, Van der Merwe
- Cons: Sexton 3
- Pen: Sexton
Ulster (12) 26
- Try: Wannenburg, Gilroy
- Cons: Pienaar 2
- Penalties: Humphreys 3, Pienaar
Leinster had their four-try bonus point in the bag before half-time as they proved too strong for Ulster in Dublin.
Richardt Strauss, Luke Fitzgerald, Shane Horgan and Heinke van der Merwe scored tries before the break.
Ireland winger Horgan added another try early in the second half before South African back row Pedrie Wannenburg forced over Ulster's first try.
Winger Craig Gilroy went over in the 75th minute and Ruan Pienaar converted to cut the deficit to eight points.
It was a spirited response by Ulster after they looked in danger of being swamped by the two-time league champions.
Leinster, even without Brian O'Driscoll, scored three tries inside the opening 13 minutes.
It was Leinster's 25th successive home league win, while Ulster still have not won in Dublin since 1999.
The winners move up to second place in the league with Ulster down to third.
Leinster got off to a dream start when Strauss burrowed over after just 70 seconds.
Jonathan Sexton kicked towards the left corner, Fitzgerald and Adam D'Arcy battled for the ball and when it went loose, Eoin O'Malley's flicked pass sent Strauss diving over.
Leinster scored again in the eighth minute with Sexton drawing two players to put Isa Nacewa through a gap on the left and he passed for Fitzgerald to ghost over in the corner.
The thid try came when Fergus McFadden's looping pass gave Horgan enough time and space to barge over in the right corner. Sexton added the extras for a 17-3 advantage.
Ulster fly-half Ian Humphreys landed his second and third penalties Sexton nailed a penalty in response before referee Pascal Gauzere reached for his yellow card when Ulster number eight Wannenburg tackled Fitzgerald without the ball.
The bonus point score came a minute later, the home forwards barging up in a maul which saw prop Van der Merwe touch down by the posts.
Then Ulster scrum-half Pienaar landed a long-range penalty in stoppage-time while Humphreys was treated for a knock.
In the second half Leinster struck again as Horgan attacked down the right, deftly collected his own chip, and breezed over for try.
Ulster's replacement, Willie Faloon, helped Wannenburg wrestle his way over for a try that the visitors' efforts deserved.
Then winger Gilroy fended off Jennings to grab his eighth league try.
Leinster: Nacewa; Horgan, O'Malley, McFadden, Fitzgerald; J Sexton, Boss; van der Merwe, Strauss, Wright, Cullen, Toner, McLaughlin, Jennings, Heaslip.
Replacements: D Kearney for Nacewa (50), Madigan for Sexton (50), Harris-Wright for Strauss (55), Ross for Wright (55), Hines for Cullen (48), O'Brien for McLaughlin (48), Healy for Jennings (76).
Not used: Reddan.
Ulster: D'Arcy; Trimble, Spence, Wallace, Gilroy; Humphreys, Pienaar, McAllister, Best, Botha, Barker, Tuohy, Diack, Henry, Wannenburg.
Replacements: Gaston for D'Arcy (66), Cave for Spence (50), P Marshall for Humphreys (72), Young for McAllister (61), Kyriacou for Best (76), Cronin for Botha (33), McComb for Barker (61), Faloon for Diack (50).
Referee: Pascal Gauzere (France)