A strong Saracens performance shattered Saints’ hopes of back-to-back titles as Jim Mallinder’s men were beaten 29-24 in the Aviva Premiership play-off semi-final.
The away side, who had sneaked into fourth on the final day of the regular-season, showed real spirit as they edged past the champions at Franklin’s Gardens.
A penalty try and an effort from Tom Wood had given Saints hope, but scores from Chris Wyles and Jamie George, allied with the boot of Owen Farrell sent Saracens to Twickenham.
The game had been level at half-time, despite Saracens being reduced to 14 men for 10 minutes when Mako Vunipola was sin-binned.
And the away side were the more assured in the second period as George’s score and Farrell’s kicking gave them the edge.
Saints were five points down with 18 minutes remaining, but they weren’t able to repeat the heroics of a year earlier, when Leicester were slayed on the way to the title.
And Farrell put the finishing touches to the victory to ensure his team avenged their agonising final defeat to Mallinder’s side in last season’s showpiece.
Saints’ chances of victory were hampered in a brutal first half that saw three members of the home team forced off through injury.
Full-back Ahsee Tuala was the first to go and with him lying prone, David Strettle kicked ahead and won the race, handing the ball to Wyles to score.
Farrell converted with aplomb and Saracens were ahead early, just as they were when Wyles opened the scoring at Milton Keynes last month.
But just as they had then, Saints responded, with Wilson’s kick putting them in position to turn up the heat.
After a couple of lineout drives, Saracens prop Mako Vunipola was sin-binned and Saints then scored from the next big shove, earning a penalty try from referee Greg Garner.
Stephen Myler levelled it up with the simple conversion and Saints had eight minutes to play with a man advantage.
But aside from one moment of panic, when Saracens were forced to scramble following a Lee Dickson break, the away side held their own well.
They were level on the scoreboard when the numbers were evened up and Saracens quickly restored their lead as Billy Vunipola won a penalty at the breakdown and Farrell kicked it.
Saints again replied quickly as Ken Pisi was taken out off the ball and Myler slotted the penalty from in front of the posts.
Saracens were winning the breakdown battle though, earning two quick penalties, the first of which was missed by Farrell, who then made the second.
Myler levelled things up with the final kick of the half, but Saints were forced into a reshuffle at the break as Wilson joined Tuala and Alex Corbisiero in exiting early.
Those injury issues saw winger Ken Pisi pushed the full-back and centre Tom Stephenson, on for Wilson at the break, playing on the wing.
Despite that, Saints were first to show in the second half as Myler landed another penalty.
In a see-saw game, Saracens weren’t behind for long as Farrell kicked to the corner and an unstoppable lineout drive brought a try for George.
The conversion gave the away side some breathing space with a 20-16 lead and Saints knew they needed the next score.
But it wasn’t to come as Farrell stuck the boot in once more with another penalty.
Saints did at least strike back soon after as Wood used a lineout drive to dot down, but Myler’s miss from the tee left his team two points behind.
Saints’ continual concession of penalties was costing them dear and yet another blow of the whistle from Garner gave Farrell three more points.
Saracens were looking strong, stopping Saints’ main weapon, the lineout drive, and the home side were running out of options.
As the clock ticked down, Saracens won yet another penalty at the breakdown, with Farrell landing it.
And despite a Myler effort and an attempt at an attack from deep in the final seconds, there was to be no late drama as Saracens secured their place at Twickenham.
Saints: Tuala (Wilson 3 (Stephenson 40)); K Pisi, G Pisi, Burrell, Elliott; Myler, Dickson (Fotuali’i 50); Corbisiero (A Waller 33), Hartley (c) (Haywood 68), Ma’afu (Denman 55); Lawes, Day (Fisher 70); Wood, Clark (Dickinson 75), Manoa.
Saracens: Goode; Wyles, Taylor, Barritt, Strettle (Ashton 60); Farrell, Wigglesworth; M Vunipola, George, Du Plessis (Figallo 60); Kruis, Hargreaves (c) (Hamilton 62); Itoje (Wray 65), Burger, B Vunipola.
Referee: Greg Garner