Northampton Saints will face Leicester in the Aviva Premiership final after recording a shock 27-13 victory over Saracens at Allianz Park on Sunday.
Sarries were undefeated at Allianz Park going into the game but found themselves 17-0 down at the break through Brian Mujati and Jamie Elliott tries, as well as seven points from Stephen Myler's boot.
A Duncan Taylor try and two Owen Farrell penalties gave Mark McCall's men hope, but Gerrit-Jan van Velze's touchdown and Myler's second three-pointer sealed the win.
The hosts went into this encounter as huge favourites having finished the regular season at the top of the league and also having reached the semi-finals of the Heineken Cup.
However, the home side were shocked by the visitors in the opening half as they played with a verve and an intensity they have rarely produced against the top teams this year.
Although Myler was off-target with his first two penalty attempts, Northampton were eventually rewarded for their dominance when Mujati finished off a typically powerful driving maul.
It got worse for the London-based outfit when Elliott touched down after scampering down the left-hand side, taking advantage of good work from Lee Dickson and Christian Day. Myler converted for the second time before adding a three-pointer late in the half to give Saints a surprise 17-0 lead at the interval.
Despite the travails of the opening period - possibly their worse display of the campaign - Sarries came out with intent after the break. Mako Vunipola was particularly prominent and David Strettle had a chance to reduce the arrears, although the wing wasted the opportunity as he was held up.
Farrell did reward his pack's efforts with successive penalties but their work was undone when the excellent Dickson sent van Velze over.
There was a glimmer of hope when Elliott was sin-binned for taking Farrell out in the air and they took advantage of the extra man when Taylor crossed the whitewash.
However, Myler eased the nerves with a late three-pointer to take Northampton into the final where they will face arch-rivals Leicester Tigers.
Pen: Farrell 2
Tries: Mujati, Elliott, Van Velze
Con: Myler 3
Pen: Myler 2
Saracens: 15 Alex Goode, 14 Chris Ashton, 13 Joel Tomkins, 12 Owen Farrell, 11 David Strettle, 10 Charlie Hodgson, 9 Neil de Kock, 8 Jackson Wray, 7 Will Fraser, 6 Kelly Brown, 5 Alistair Hargreaves, 4 Steve Borthwick (c), 3 Matt Stevens, 2 Schalk Brits, 1 Mako Vunipola.
Replacements: 16 John Smit, 17 Rhys Gill, 18 Carlos Nieto, 19 Mouritz Botha, 20 George Kruis, 21 Richard Wigglesworth, 22 Duncan Taylor, 23 Chris Wyles.
Northampton: 15 Ben Foden, 14 Ken Pisi, 13 James Wilson, 12 Luther Burrell, 11 Jamie Elliott, 10 Stephen Myler, 9 Lee Dickson, 8 Samu Manoa, 7 Tom Wood, 6 Calum Clark, 5 Christian Day, 4 Courtney Lawes, 3 Brian Mujati, 2 Dylan Hartley (capt), 1 Soane Tonga'uiha.
Replacements: 16 Mike Haywood, 17 Alex Waller, 18 Tom Mercey, 19 Phil Dowson, 20 GJ Van Velze, 21 Martin Roberts, 22 Ryan Lamb, 23 Tom May.
Referee: JP Doyle
Assistant referees: Paul Dix, Peter Huckle
TMO: John Burtenshaw