Two first-half tries from Sean O'Brien stunned Ulster 30-13 as Leinster moved above their rivals in the Magners League table on Monday.
Former Ulster scrum-half Isaac Boss played a central role for a Leinster side which was without nine regulars, setting up number eight and man of the match O'Brien for his scores while Shane Horgan's second-half try extinguished Ulster's already undermined challenge.
Full-back Isa Nacewa also made a handsome contribution to Leinster's cause, scoring 15 points with the boot and providing an assist for Horgan.
Ulster were also missing players due to a combination of Ireland's player management scheme and injuries, but they simply had no answer to Leinster's power and dynamism.
Playing into a strong wind, Ulster's early ploy of picking and driving almost immediately came unstuck as Robbie Diack was pinged for holding on, but thankfully for the hosts Nacewa went wide with the penalty attempt.
That was a warning to Ulster but they did not learn, and after just seven minutes Boss broke through some weak first-up tackling and made the chance for O'Brien who steamed in under the posts.
The conversion was a formality for Nacewa but then, four minutes later, Leinster scored a copycat try with Boss drawing BJ Botha and sending O'Brien barrelling through again to once more dot down under the posts to give Nacewa another simple conversion.
Ulster managed to recover with a penalty from Niall O'Connor after Mike Ross was penalised at a scrum in the wake of some good approach play from Johann Muller.
There was little sign of a significant Ulster revival, and Nacewa's first penalty kept Leinster 14 points in front.
O'Connor slotted a second penalty after the visitors infringed under their own posts following a rare Ulster surge with Nevin Spence and Craig Gilroy handling.
But Leinster kept on the pressure and another Nacewa penalty put them 20-6 up at the break, the final play of the half being a missed penalty from inside his own half by Nacewa.
On the resumption, the pain only continued for Ulster, with Nacewa landing an early penalty after an Ulster midfield move was snuffed out.
From there Leinster pressed on and following a number of drives towards Ulster's line, the ball was moved with Brian O'Driscoll helping it on its way before Nacewa provided the assist for Shane Horgan to smash over in the right corner.
Nacewa superbly converted and at 30-6 there was never any way back for Ulster. Winger Gilroy's late score was mere consolation, as was O'Connor's conversion.
Pen: O'Connor 2
Tries: O'Brien 2, Horgan
Con: Nacewa 3
Pen: Nacewa 3
Ulster: 15 Adam D'Arcy, 14 Craig Gilroy, 13 Nevin Spence, 12 Ian Whitten, 11 Simon Danielli, 10 Niall O'Connor, 9 Ruan Pienaar, 8 Robbie Diack, 7 Chris Henry, 6 Pedrie Wannenburg, 5 Dan Tuohy, 4 Johann Muller (captain), 3 BJ Botha, 2 Nigel Brady, 1 Paddy McAllister.
Replacements: 16 Andi Kyriacou, 17 Declan Fitzpatrick, 18 Bryan Young, 19 Tim Barker, 20 Willie Faloon, 21 Paul Marshall, 22 Luke Marshall, 23Tommy Seymour.
Leinster: 15 Isa Nacewa, 14 Shane Horgan, 13 Brian O'Driscoll, 12 Fergus McFadden, 11 Dave Kearney, 10 Shaun Berne, 9 Isaac Boss, 8 Sean O'Brien, 7 Dominic Ryan, 6 Rhys Ruddock, 5 Devin Toner, 4 Leo Cullen (c), 3 Mike Ross, 2 Jason Harris-Wright, 1 Heinke van der Merwe.
Replacements: 16 Aaron Dundon, 17 Jack McGrath, 18 Clint Newland, 19 Ed O'Donoghue, 20 Ben Marshall, 21 Paul O'Donohoe, 22 Ian Madigan, 23 Andrew Conway.
Referee: George Clancy