The door to the rugby Pantheon was always going to swing open if Leinster could secure a third Heineken Cup win in four seasons, but they hurried the process along by kicking the thing off its hinges with this emphatic victory at Twickenham.

Ulster fought bravely throughout and had a couple of marvellous periods of pressure, but the class and ruthless efficiency of the Dubliners gave them a huge advantage when it mattered.

Only four-times winners Toulouse can now rival Leinster's claim to be the greatest team in Heineken Cup history, but the French giants were never as dominant for seasons on end as Leinster have been. Toulouse could slip up at times, but this Leinster side give no hint of that. They weathered Ulster's periods of ascendancy, took their punishment on the scoreboard, then hammered back upfield and dished out more of their own.

By the end, as replacement hooker Sean Cronin coasted over for Leinster's fifth try, Ulster were dead on their feet, slaughtered in the final stages of a match in which they had been admirably competitive. The try-count, the final scoreline and the margin of victory were all records; frankly, it is hard to imagine any side on earth, bar a top international team, living with Leinster at the moment.

It helped, of course, that their big players stood up to the task. Sean O'Brien was immense in the back row, Brian O'Driscoll played with wit and ingenuity, and Jonny Sexton was superbly composed. More than that, though, this was a marvellous team performance, with not a weak link to be seen anywhere in the Leinster ranks.

In fairness to Ulster, they obviously had no intention of playing along with a script that said they lacked a cutting edge behind the scrum. Within the first five minutes, both centres, Paddy Wallace and Darren Cave, had made decent line-breaks through the Leinster midfield, and there had also been a tantalising glimpse of Craig Gilroy's running skills. When Ruan Pienaar prodded Ulster in front with a penalty after seven minutes, it was no more than his side deserved.

Yet even at that stage there was a sense that Ulster's performance was being driven along by passion rather than cool-headed class. A sense, too, that Leinster were not really being hurt by the onslaught. Of all Leinster's qualities, the one that is most overlooked is their defensive organisation, and it allowed them to weather the storm with only modest damage on the scoreboard.

And if Leinster are tidy at the back, they can be devastating going forward. It took them more than 10 minutes to make their first trip into the Ulster 22, but there was nothing tentative about them when they got there. Granted, they were helped when Ulster won a ball at a scrum and then failed to clear the danger, but Leinster were voracious when that first chance came their way.

Pedrie Wannenburg, a colossus against Edinburgh in the semi-final, rumbled away from that scrum, a few yards short of the 22. The expectation was that Ulster would then leather the ball into touch, but instead it popped out of the ruck on the Leinster side. From there, Gordon D'Arcy and Mike Ross hammered on to take play close to the Ulster line, with O'Brien powering over from short range – through a feeble tackle attempt by the hapless Wannenburg – for the game's opening try.

Leinster had another try on the board before half time. Again, it came down to Ulster's failure to look after scrum possession, although the blame on this occasion probably belonged to their front row. Wherever the fault lay, Leinster were never likely to show mercy, and they attacked the misshapen Ulster defence with venom. The killer touch came from O'Driscoll, whose brilliantly disguised reverse pass to O'Brien allowed the flanker a clear run into the 22. O'Brien was brought down a couple of yards short, but Leinster were swarming forward in support and a swift pass to Cian Healy allowed the bull-necked prop to drive low and hard over the whitewash to claim the second touchdown.

Pienaar did reduce the interval deficit to 14-6 with an astonishing 60-metre penalty, but the most powerful images of the closing moments of the period were of Paddy Jackson, the young Ulster fly-half, who wasted two gilt-edged chances by ignoring a clear overlap as his side streamed towards the right corner and then sclaffed an easy drop-goal attempt wide of the posts.

Jackson's nightmare continued into the early moments of the second half when, mistakenly believing that he was free to kick to touch from inside the 22, he only succeeded in gifting possession to Leinster. Again, they were ruthless with the opportunity. From the line-out on the left side, they formed a fearsome maul, driving deeper and deeper into Ulster territory, blowing opponents away as they did so. In panic, Ulster collapsed the maul a couple of yards short, and referee Nigel Owens had no option but to award a penalty try. As Sexton converted, Jackson, his opposite number, trudged disconsolately towards the touchline, ignominiously replaced after just 45 minutes.

Ulster pressure produced a deserved try for lock Dan Tuohy, but their own fans must have feared the response. And with due cause, for Leinster cranked it up again, with Sexton collecting a couple of penalties before Heinke Van der Merwe and Cronin delivered the last two tries.

So the Heineken Cup will be locked away in the Leinster cabinet again. And their greatness is pretty secure as well.

Leinster: R Kearney (D Kearney, 72); F McFadden, B O'Driscoll (D Kearney, temp, 67 - 72) , G D'Arcy, I Nacewa; J Sexton (I Madigan, 74), E Reddan (J Cooney, 74); C Healy (H Van der Merwe, 61), R Stauss (S Cronin, 67), M Ross (N White, 69), L Cullen (captain; D Toner, 57), B Thorn, K McLaughlin (S Jennings, 61), S O'Brien, J Heaslip.

Ulster: S Terblanche; A Trimble, D Cave (A D'Arcy, 78), P Wallace, Gilroy; P Jackson (I Humphreys, 45; P Marshall, 69), R Pienaar; T Court (P McAllister, 75), R Best (N Brady, 78), J Afoa (D Fitzpatrick, 74), J Muller (captain), D Tuohy (L Stevenson, 77), S Ferris, C Henry (W Faloon, 67), P Wannenburg.

Referee: N Owens (Wales). Attendance: 81,744