Northampton maintained their unbeaten record in the Heineken Cup this season, beating Perpignan 23-7 in their semi-final at stadium:mk on Sunday.
Saints led from start to finish and never realistically looked like losing after taking a 20-7 lead into the half-time break.
Northampton will now face Leinster in the final at the Millennium Stadium in Cardiff on May 21.
Tries from Ben Foden and Jon Clarke in the first half-an-hour put the hosts in pole position and Perpignan had neither the imagination nor the firepower to launch a comeback.
The much-anticipated clash between two formidable packs didn't disappoint and the 'home' front row's contribution - especially in the second half - was immense.
Northampton did however struggle at the line-out all day. Having scored their only try from a textbook line-out and maul, Perpignan turned down a number of kickable penalties as they looked for a repeat effort.
As it turned out, Northampton saw them coming and could organise their defence as a consequence. The Catalans had few other options though as they failed to seriously threaten by any other means.
The English side opened the scoring on the quarter-hour mark after Phil Dowson made a 20 metre break up the centre of the field. The Catalan defence was slow in reorganising and Ben Foden had an easy run-in from the recycled ball.
Soon afterwards a dubious call from referee George Clancy had the visitors rattled. Clancy wrongly adjudged David Marty offside from a clever chip from Nicolas Laharrague, allowing Stephen Myler to add three more points from long range.
USAP clearly felt aggrieved and their apparent loose of concentration over the next few minutes cost them dearly.
The Perpignan defence was nowhere to be seen when Jon Clarke cruised over for Saints' second try. Wing Julien Candelon then saw yellow for clumsily taking Lee Dickson out in the air.
After a strong start, the visiting scrum began to buckle and Myler could extend the lead to 20-0 with half time looming large.
The visitors were given a glimmer of hope just before the break however when they pushed their way over off the back of a 5 metre line-out.
The second half provided just three points - again from Myler's boot - as Perpignan's one-dimensional tactics were unable to crack the Northampton defence.
Man of the match: A number of candidates here. The Northampton back-line provided both their tries and completely outclassed the visitors. Phil Dowson had a huge game in the back row and created the first try. But we'll go with collective award for the Northampton front row. Brian Mujati, Dylan Hartley, Soane Tonga'uiha struggled at the first few scrums but came back to dominate the set piece. All three of them made power runs and a handful a thundering tackles.
Tries: Foden, Clarke
Cons: Myler 2
Pens: Myler 2
Yellow card: Candelon (Perpignan - 32nd min- dangerous tackle)
Northampton: 15 Ben Foden, 14 Chris Ashton, 13 Jon Clarke, 12 James Downey, 11 Paul Diggin, 10 Stephen Myler, 9 Lee Dickson, 8 Roger Wilson, 7 Phil Dowson, 6 Calum Clark, 5 Christian Day, 4 Courtney Lawes, 3 Brian Mujati, 2 Dylan Hartley (capt), 1 Soane Tonga'uiha.
Replacements: 16 Brett Sharman, 17 Alex Waller, 18 Tom Mercey, 19 Mark Sorenson, 20 Mark Easter, 21 Stuart Commins, 22 Shane Geraghty, 23 Joe Ansbro.
Perpignan: 15 JÃ©rÃ´me Porical, 14 Adrien Plante, 13 David Marty, 12 Gavin Hume, 11 Julien Candelon, 10 Nicolas Laharrague, 9 David Mele, 8 Damien Chouly, 7 Bertrand Guiry, 6 GrÃ©gory Le Corvec, 5 Robins Tchale Watchou, 4 Rimas Alvarez Kairelis, 3 Nicolas Mas, 2 Guilhem Guirado, 1 Perry Freshwater.
Replacements: 16 Charles Geli, 17 Kisi Pulu, 18 JÃ©rÃ´me Schuster, 19 Henry Tuilagi, 20 Kevin Boulogne, 21 Manny Edmonds, 22 Joffrey Michel, 23 Guillaume Vilaceca.
Referee: George Clancy (Ireland)
Assistant referees: Alain Rolland (Ireland). Simon McDowell (Ireland)
Television match official: Tony Redmond (Ireland)
Timekeeper: Brian Abrahams (England)