Leinster conjured the greatest comeback in Heineken Cup final history to collect their second European title and leave Northampton painfully reflecting on a season without silverware.
Ireland fly-half Jonathan Sexton scored 28 of Leinster's points - two tries, four penalties and three conversions - after Saints led 22-6 at half-time in a remarkable Millennium Stadium contest.
Northampton appeared to be home and dry following first-half touchdowns for flanker Phil Dowson, full-back Ben Foden and captain Dylan Hartley in pursuit of England's first European crown since Wasps lifted the trophy four years ago.
Fly-half Stephen Myler added two conversions and a penalty for good measure, but Leinster delivered a calculated response as they chased a second Heineken crown in three seasons.
They moved effortlessly ahead by the hour mark, before a try from their Scotland international lock Nathan Hines sealed a spectacular success underpinned by them scoring 27 unanswered second-half points.
Northampton, beaten by Leicester in last weekend's punishing Aviva Premiership play-off at Welford Road, will wonder until this time next term how they could implode in such fashion.
Leinster though, showed them the harsh reality of life at European rugby's sharp end, with Ireland international Sexton taking command just when his team needed it most.
It was a masterful display by Leinster's playmaker, who finished two points short of equalling Diego Dominguez's Heineken record haul for Stade Francais in the 2001 final against Leicester.
But while the favourites celebrated, Northampton could only reflect on what might have been.
How Saints recover from such a setback is anyone's guess, but the harsh reality is they have seen their hopes of a domestic and European double disappear without trace inside seven days.
Both teams were unchanged from their semi-final victories over Toulouse and Perpignan, respectively, although there remained question marks surrounding talisman Brian O'Driscoll after he limped off during the Magners League play-off win against Ulster last weekend.
Northampton though, were in no mood to confirm their underdog status, and initial domination was rewarded with a try inside eight minutes.
Leinster conceded early territory, and despite Sexton's attempts to relieve the pressure, Northampton sensed there was an opportunity they had to prosper from.
And it was Dowson who pounced, crashing over from close range for a try that Myler converted as Saints enjoyed a dream start to lie 7-0 ahead without Leinster launching a meaningful attack.
Myler and Sexton then exchanged penalties as Northampton's scrum began to assert authority, although Leinster had a gilt-edged scoring chance that went begging.
Wing Shane Horgan linked superbly with flanker Sean O'Brien, creating an opening for O'Driscoll, but Foden completed a magnificent cover tackle.
And even when Saints' South African prop Brian Mujati was sin-binned for pulling back his opposite number Cian Healy off the ball, Northampton did not remotely threaten to surrender set-piece control.
Although they were temporarily reduced to seven forwards, Saints' hunger for the battle ensured Leinster remained on the back foot, lacking a way of nullifying their opponents' power.
And the punishment continued when a territory-hungry Saints pack ensured Leinster's torture continued by ensuring quick scrum ball and setting up another attack.
Myler scooted clear in midfield and, before Leinster could regroup, Northampton had enough players out wide that allowed Foden plenty of options before he claimed the try himself.
Myler again converted and, despite Sexton slotting a second penalty just before half-time, Northampton proved outstanding value for their advantage.
And they extended the lead on the stroke of half-time when Hartley powered over from close-range, handing Leinster a mountain to climb.
Leinster, 3-0 down on tries, knew they had to open the second-half scoring or face oblivion, but they came up trumps when Sexton weaved his way over on an angle and then added the extras via a ricochet off the post.
They thought they had scored again just seven minutes later when centre Gordon D'Arcy crossed Saints' line, but brilliant defensive work from wing Paul Diggin prevented the touchdown.
It proved no more than a respite though, as further Leinster pressure resulted in Sexton claiming his second try that he again converted, cutting Saints' interval lead from 16 points to two.
Sexton, who could not put a foot wrong, then kicked a 40-metre penalty to put Leinster ahead for the first time during a third quarter that had seen his team score 17 unanswered points.
Northampton were at sixes and sevens, but their misery was not complete as another Sexton penalty, followed by Hines' try that Sexton converted, left Saints in disarray at 11 points adrift with no way back.