Academy graduate Alex Waller was the hero as his last-gasp extra-time try gave Saints a 24-20 win against Saracens and Aviva Premiership glory at Twickenham.
Waller, who had returned to the field following a spell off the field for a blood injury, stretched out an arm with less than two minutes of the match remaining and, after numerous replays, TMO Graham Hughes gave the try to send the Northampton faithful into ecstasy.
Stephen Myler added the extras to seal a four-point win that will be celebrated for years to come at Saints, who claimed their first Premiership title and a double win, after the Amlin Challenge Cup triumph eight days earlier.
Saracens had looked to snatch the glory away so cruelly when replacement fly-half Charlie Hodgson’s kick six minutes from the end of the second period of extra-time gave his team a 20-17 lead.
But Waller pounced to bring the trophy back to Northampton.
An attritional first 80 minutes had ended 14-14, with Ben Foden and George Pisi dotting down in normal time for Saints.
Hodgson had a chance to win it for Sarries, but his conversion from Marcelo Bosch’s try struck the outside of the right post.
That took the game to extra-time and after Myler and Hodgson exchanged penalties, the Saracens man put his team ahead.
But Waller had the final say and Saints celebrated their stunning triumph to a backdrop of green, black and gold.
The game always promised to be tight, with the first five minutes nip and tuck.
Saints were the first to show their attacking intent as Foden and George North attempted to burst from deep, but Sarries’ ‘Wolfpack’ defence held firm.
And Owen Farrell put the men in black and red ahead on 11 minutes, landing a penalty after Saints were penalised for going in at the side.
Saracens were dominating possession and after Chris Ashton brilliantly caught a high ball, Ken Pisi infringed, giving Farrell the chance to double his team’s lead. He took it.
Saints were kicking away possession when going through the hands was the better option, and they were being made to pay.
Sam Dickinson was caught offside and that handed Saracens another penalty, but, this time, Farrell was unable to bisect the posts.
Saints, though, needed some possession. They needed some points. But Saracens were tightening their grip on the game.
North did well to cover as David Strettle eyed a score and Saints stood tall, winning a turnover little more than five metres from their own line.
Saints needed a spark, and they got it from Ken Pisi, who shot out of his own half and superbly dragged his team into the Sarries 22.
Myler kicked for the corner, showing Saints’ determination to put the pressure on Saracens and that was exactly what they did, moving the ball from right to left for Foden to score.
It was a stunning score, made by some superb offloading, and Myler superbly added the conversion to take his team into the lead for the first time.
But Saracens responded, surging into Saints territory and attempting to put the squeeze on from a lineout five metres out.
Saints held firm, though, staying strong in the face of a drive that looked likely to take Sarries over the line.
And Jim Mallinder’s men won a penalty from a scrum just before the break, ensuring there would be no repeat of the late first-half drama of a year earlier, when Leicester won a penalty and Dylan Hartley was sent off.
Saints had needed to scale a mountain in that clash with Tigers, but this time they were one point up heading into the second half.
They knew they needed to up their game, though, as Sarries had dictated proceedings during the first period and were on the front foot from the off in the second.
And Farrell was soon booting his team back in front as the pressure told on Saints, who were struggling to relieve the pressure.
When they did, they were unable to take a huge chance as Myler’s lofted pass was far too long for any of his team-mates and Saracens escaped.
Myler was again guilty of letting Saracens off the hook soon after as his grubber kick was wayward, giving the opposition possession back.
Saints needed their leaders to stand up and on came Hartley and Phil Dowson in a bid to keep the ship steady.
Hartley’s first lineout was stolen, but some huge defending from Saints ensured Saracens wouldn’t cross the line, with a penalty won to turn down the heat.
Saints used the possession to fly up the other end and a fine grubber kick from Myler released George Pisi, who scored.
Myler executed the conversion superbly from the left touchline and Saints held a 14-9 lead with 20 minutes to go.
Saracens looked to have an immediate reply as Farrell latched on to Chris Wyles’ pass to score, but the TMO intervened, asking if referee JP Doyle wanted to review it for a forward pass in the build-up and the try was disallowed.
The Saints fans roared, feeling it might just be their day and Sarries were struck with another blow as Farrell had injured himself when celebrating the try,
The fly-half pulled a muscle while booting the ball into the crowd and the Sarries 10 was forced off, with Hodgson replacing him.
Hodgson was welcomed to the game with a monstrous hit from Courtney Lawes, whose tackle drew groans from the crowd.
That lifted the Saints fans, who were doing their best to cajole their team out of their own half and some monstrous defending was needed to stop Saracens in their tracks.
Hartley won a turnover and James Wilson, on for George Pisi, booted the ball into touch to gain his team some territory.
But back came Saracens, winning a penalty from the Saints lineout and another wave of pressure was applied.
Hodgson kicked a penalty to the corner, with his team smelling blood, and a they soon had their score, with Bosch diving over.
Hodgson hit the post with the conversion, leaving the scores tied with little more than six minutes to play.
Nerves were frayed, bodies bruised and Saracens were on the rampage, going through the gears as Saints desperately tried to get hold of them.
A steal and a Tom Wood kick got the ball clear and after replacement Lee Dickson kicked the ball away, it was bundled into touch, with 20 minutes of extra-time beckoning.
The tension around Twickenham was palpable, with fans barely believing what they were witnessing as first period of extra-time began.
Saints got off to the best start, with Myler finding the energy to lash the ball between the posts from the tee.
But Wilson failed to gather the kick-off cleanly and Saracens were level immediately as a scrum penalty gave Hodgson the chance to land a penalty.
The pattern of the game then continued, with Sarries in the ascendancy, but Jackson Wray’s surge towards the line didn’t yield a try, as Doyle pulled play back for an earlier offence.
Doyle informed Saracens at half-time in extra-time that Saints had ‘an away goal’, meaning the men in lime would win if the scores remained level due to having scored more tries.
Sarries heeded that warning and Hodgson stroked what looked to be the winning penalty through the posts.
But Waller wouldn’t let it lie, making the most of his team’s relentless surges towards the line.
And after the TMO gave the decision, the Saints fans let out the loudest of roars, with Myler adding the gloss to the most memorable of days in the capital.
Saints: Foden; K Pisi (Stephenson 90), G Pisi (Wilson 62), Burrell, North; Myler, Fotuali’i (Dickson 51); Corbisiero (A Waller 55), Haywood (Hartley 55), Ma’afu (Mercey 51); Manoa (Day 57), Lawes; Clark (Dowson 57), Wood (c), Dickinson.
Saracens: Goode; Ashton, Bosch, Barritt, Strettle (Wyles 57); Farrell (Hodgson 65), de Kock (Wigglesworth 51); Barrington (Gill 83), Brits, Stevens (Johnston 55); Borthwick (c), Botha (Hargreaves 51), Brown, Burger (Wray 51), B Vunipola.
Replacements not used: George.