Their five tries was a final record and the victory was the highest score and biggest winning margin in the competition's 17-year history, all watched by a Heineken Cup record crowd of 81,774.
Replacements Heinke Van der Merwe and Sean Cronin put the icing on the cake with late tries to spark wild scenes in the temporarily Irish corner of south-west London.
Leinster's victory made them the first team to go through a Heineken Cup campaign unbeaten and with three titles they move second behind Toulouse (four) in the roll of honour of Europe's elite club competition.
The win also meant New Zealander Brad Thorn completed a unique triple, adding the Heineken Cup title to the World Cup he won with the All Blacks in October last year and the Super Rugby title he picked up with the Canterbury Crusaders in 2008.
Ulster came careering out of the blocks, securing the first penalty of the match within five minutes when Leinster made a couple of early mistakes at the breakdown. The Belfast-based side decided that the kick was outside even the long-kicking Ruan Pienaar’s range and kicked for territory, before keeping Leinster pinned back deep in their own half with wave-after-wave of confident attacks.
It did not take long for Ulster to make that pressure tell, Pienaar taking his second spot kick and drilling the ball in between the posts for a 3-0 lead in the eighth minute.
Leinster had a chance to level up almost immediately but the usually metronomic Johnny Sexton somehow managed to pull his kick from the halfway line wide, despite comfortably having the distance. However, the early pressure by Ulster seemed to spur Leinster into action, the defending champions showing the slick passing they are renowned for as they started to push Ulster back deep into their own half.
After waking from their early slumber it took just minutes for Leinster to force their way into the lead, O’Brien battering his way over the try-line despite the best attempts of Pienaar with a last-gasp tackle. Referee Nigel Owens sent the decision up to the television match official to check the grounding from the Leinster flanker but replays showed O’Brien was just on the line as he forced the ball down and Sexton quickly added the extras to maximise the score.
Leinster combined to score another classic team try 20 minutes later, Healy the man to dive over after O’Brien and Eoin Reddan had taken advantage of a gap in the Ulster line.
Sexton added another two points to leave the defending champions looking comfortable heading into the interval before Pienaar gave Ulster hope with the last kick of the half, after Rob Kearney was penalised at the breakdown.
But Ulster could not build on that hope with things quickly going downhill after half-time when another mistake from a nervy Paddy Jackson ultimately lead to a penalty try for Leinster; Ulster pulling down a rolling maul as the Dublin side charged towards the line.
Unsurprisingly, Sexton had no troubles adding the conversion from right in front of the posts and Ulster found themselves more than two converted tries behind just six minutes after the re-start.
The underdogs were afforded a brief glimpse of hope when O’Brien was harshly penalised for a high tackle in the 49th minute, allowing Pienaar the kick that brought the deficit back down to 21-9. But a sloppy penalty from Carl Henry, playing the ball off his feet, immediately allowed Sexton to re-establish the 15 point lead.
That third kick from Sexton heralded the door slamming shut in Ulster’s face as Leinster looked increasingly less likely to allow their opponents back into the match, despite Dan Tuohy scoring a consolation try for Ulster just after the hour mark.
Wallace broke through the Leinster line before flinging the ball wide to Tuohy, who forced his way over in the corner. Ulster really needed to add the conversion to put any real pressure on Leinster, although even then a comeback would have been a long shot, but will be left to rue their chances after Pienaar’s admittedly tricky kick sailed across the front of the goal and past the right upright.
Sexton added another penalty with 11 minutes remaining on the clock to take his side to a 27-14 lead, which told the tale of their control on the match.
But a shocking final 10 minutes from Ulster were to come, allowing Leinster to end with a scoreline that unfairly reflected Ulster’s contribution to the match.
First Stefan Terblanche was sent to the sin-bin for a poor tip tackle on substitute Sean Cronin, a moment of stupidity that also allowed Sexton to bring Leinster’s tally up to 30 points.
Easily exploiting their one-man advantage, Leinster crossed over for a fourth try just four minutes later, van der Merwe the man to touch down in the left corner before Fergus McFadden, taking over kicking duties from the substituted Sexton, failed to add the conversion.
But Cronin’s last-minute try, this time in the right corner, afforded McFadden the chance to make amends, this winger this time landing the conversion to complete a highly impressive win for Leinster.
Leinster still have a further chance for glory this season when they take on Ospreys in the final of the Pro12 at the RDS next weekend.