The form line had always said Leinster would win this Heineken Cup final under the Millennium Stadium roof, as they had a stronger squad than Northampton and had come through via a much tougher route. Yet for one half of eye-rubbing, logic-defying rugby, the Saints laughed at the form line. It took a combination of the exceptional skills of Jonny Sexton, Leinster's Ireland fly-half, and a staggering redistribution of wealth in the forwards to make a flatline of the English side's European dream.
It is tempting to believe something profound happened at half-time, at which point Northampton led 22-6 with three tries to none. As if we had not had enough symbolism during the Queen's state visit to Ireland, the pre-match show had invited us to worship the trophy as it rose like an old-time cinema organist from inside a scale model of the stadium – the bowl of which was spouting flames, naturally.
It was daft but somehow apt, as you sensed a bonfire must have been set in the Leinster dressing room at the interval. Afterwards Leo Cullen, the captain, said his side had mustered around their forwards coach, Greg Feek, to rejig their scrum and "lock down" Northampton, as Feek's fellow New Zealander, the head coach Joe Schmidt put it. It is difficult to recall such a transformation – Northampton's dominant scrum began to be shoved around like a supermarket trolley on a skidpan. Certainly Leinster's comeback was a record for a Heineken final, outdoing Bath's recovery from 15-6 down to beat Brive in 1998.
Yet there was a more prosaic truth too. Northampton, whose six league defeats in mid-season saw them slip to fourth place and a Premiership semi-final defeat at Leicester, simply ran out of gas. They have been reliant on not much more than their first-choice XV – and one assembled at less expense than the Irish province, who have now joined Toulouse, Munster, Leicester and Wasps as multiple European winners. "Fatigue was an issue for Northampton in the second half," said Schmidt.
His opposite number, Jim Mallinder, appeared watery-eyed but proud as he said of a second season of near misses: "We told the players to keep playing but be aware – Leinster are a dangerous side. Hopefully we can stay up there and win one of these big 'uns next year."
Northampton at the start were more on their toes than Leinster; cuter and cleverer. A familiar short-side ploy off a scrum midway between the posts and the left wing brought their first try, after six minutes. Paul Diggin crept in close and made a little ground and with Leinster painfully slow to react to the danger, Calum Clark fed his fellow flanker, Phil Dowson, to score. Stephen Myler's conversion had the ring of confidence about it, too.
Leinster's defence was all over the shop. You wondered whether Brian O'Driscoll was anywhere near fit after the knee injury that obliged him to limp out of the Magners League semi-final nine days ago. Tight-five forwards were tackling where backs should have been and Northampton's scrum did almost as it pleased.
Sexton kicked a 45-metre penalty and Myler replied after a buckled Leinster scrum. A yellow card to the Northampton prop Brian Mujati in the 26th minute, for tackling Cian Healy without the ball, was scarcely a jolt. Saints put a centre, James Downey – a Dubliner, at that – in the scrum and rattled Leinster back again. And with 14 men Saints scored their second try. Leinster lost a scrum on their put-in in the 22, Myler skipped free and Ben Foden cantered past some soft tackling. Myler made it 17-3 and, following a Sexton penalty for a high tackle on Gordon D'Arcy, another easy beat by Clarke took him into the 22, Leinster scrabbled and after a jink by Chris Ashton on the right the forwards forced Dylan Hartley over for that16-point lead.
Northampton, with eight European wins out of eight, knew that no unbeaten team has won the final. Leinster had knocked out England's top two, Leicester and Saracens, and three of the top four in France, Toulouse, Racing Métro and Clermont. With a more mobile openside, Shane Jennings, on the field and the scrum sorted out, Leinster's key men – O'Driscoll, Jamie Heaslip, Sean O'Brien, Isa Nacewa, Richardt Strauss – began running hard and straight past suddenly slack Northampton shoulders. Most of all Sexton showed once again why he is the most exciting talent in his position in Europe. He scored two of Leinster's three tries between the 44th and 65th minutes.
O'Driscoll, Heaslip and Nacewa paved the way for Sexton to skirt Soane Tonga'uiha, and Sexton converted; D'Arcy was held up by Diggin and Foden but Sexton, at thrilling pace, looped round Heaslip. With two conversions and a penalty when Northampton's scrum was in reverse Sexton took his side in front, 23-22 after 56 minutes. Then Dowson went to the sin-bin on a marginal in-at-the-side call. That gave Sexton a fourth penalty: he had equalled Brive's Sébastien Carrat in 1997 and Leon Lloyd of Leicester in 2001 by scoring two tries in a final, and if Diego Dominguez's 30 points from '01 were beyond him, thousands singing "Come on you boys in blue" did not care.
When a succession of pick-and-goes was finished by Nathan Hines, with Sexton converting, the result was beyond doubt. Foden and Ashton had a rare raid but the England wing was easily caught and soon limped off, lame and sad of face.
Ten of the previous 11 finals had been decided by one score. Not this one. Leinster were too good for that.
Leinster I Nacewa; S Horgan, B O'Driscoll, G D'Arcy (F McFadden, 68), L Fitzgerald; J Sexton (I Madigan, 77), E Reddan (I Boss, 72); C Healy (H van der Merwe, 59) R Strauss (J Harris-Wright, 78), M Ross (S Wright, 77), L Cullen (capt), N Hines (D Toner, 77), K McLaughlin (S Jennings, 40), J Heaslip, S O'Brien.
Northampton Saints B Foden; C Ashton (S Commins, 77), J Clarke, J Downey (J Ansbro, 66), P Diggin; S Myler (S Geraghty, 66), L Dickson; S Tonga'uiha (A Waller, 66), D Hartley (capt, B Sharman, 69), B Mujati (T Mercey, 66), C Lawes, C Day (M Sorenson, 77), C Clark (T Mercey, 27-36), P Dowson, R Wilson (M Easter, 63-69).
Referee R Poite (France).
Tries: Dowson, Foden, Hartley
Tries: Sexton 2, Hines
Cons: Sexton 3
Pens: Sexton 4