Northampton's Heineken Cup dream was rudely interrupted by Perpignan on Friday, with the Catalans cruising to a 29-13 win.
From the off the home side, roared on by a vocal home crowd, dominated the collisions, eking out an early penalty try with some magnificent scrums and then opening up a healthy half-time lead with a peach of a try from David Marty.
For Northampton, the game was in stark contrast to their opener, when they lowered the colours of two-time European champions Munster.
However Perpignan had lost just twice in 28 Heineken Cup games at Stade Aime Giral and were hurting following their 9-8 defeat at Treviso, and they made a lively start as they looked to get their European campaign back on track.
Northampton's Lee Dickson saw his kick charged down and Dylan Hartley threw an unnecessary pass that eventually allowed Porical the first score with a penalty.
More points could have followed but Jean-Pierre Perez dropped a pass with the try line at his mercy while Neil Best managed to hold up Julien Laharrague over the line.
However Perpignan had a clear edge in the scrum and after Saints prop Santiago Bonorino was warned for collapsing the scrum for a third time, Welsh referee Nigel Owens awarded a penalty try after 15 minutes at the fourth time of asking.
Porical converted and then exchanged penalties with Shane Geraghty before Ashton went over after 26 minutes, winning the race for his own kick as the bounce evaded two defenders.
However Geraghty missed the conversion and Perpignan struck for a second time just before half-time.
Laharrague's kick split Northampton's defence, and was collected and shipped on in one move by Maxime Mermoz to leave Marty with a straight sprint for the line from 40 metres to open a convincing lead at half-time.
Tuilagi thought he had extended the lead but his try was ruled out for a forward pass from Perez and Northampton were forced into a desperate defensive stand on their own try line.
However Ashton and Jon Clarke combined with Bruce Reihana to launch a stunning counter-attack that ended with Soane Tongauiha's scoring pass to replacement prop Mujati.
However Geraghty was again off-target and despite Best and Phil Dowson going close, it was the right boot of Porical that produced the only further points, kicking three more penalties to complete a comfortable win.
Man of the match: Ben Foden and Chris Ashton covered themselves in glory for the Saints, but for a constant attacking thorn in a side, you could look no further than Perpignan wing Farid Sid, who broke the line at every step.
Tries: Penalty try, Marty
Cons: Porical 2
Pens: Porical 4
Tries: Ashton, Mujati
Perpignan: 15 Jérôme Porical, 14 Farid Sid, 13 David Marty, 12 Maxime Mermoz, 11 Julien Candelon, 10 Nicolas Laharrague, 9 Nicolas Durand, 8 Henry Tuilagi, 7 Jean-Pierre Perez, 6 Gerrie Britz, 5 Robins Tchale Watchou, 4 Rimas Alvarez Kairelis, 3 Nicolas Mas (capt), 2 Guilhem Guirado, 1 Perry Freshwater.
Replacements: 16 Marius Tincu, 17 Jérôme Schuster, 18 Kisi Pulu, 19 Guillaume Vilaceca, 20 Ovidiu Tonita, 21 Steve Meyer, 22 Florian Cazenave, 23 Christophe Manas.
Northampton: 15 Ben Foden, 14 Chris Ashton, 13 Jon Clarke, 12 James Downey, 11 Bruce Reihana, 10 Shane Geraghty, 9 Lee Dickson, 8 Roger Wilson, 7 Neil Best, 6 Phil Dowson, 5 Juandre Kruger, 4 Courtney Lawes, 3 Santiago Bonorino, 2 Dylan Hartley (capt), 1 Soane Tongauiha.
Replacements: 16 Brett Sharman, 17 Regardt Dreyer, 18 Brian Mujati, 19 Ignacio Fernandez Lobbe, 20 Mark Easter, 21 Alan Dickens, 22 Steve Myler, 23 Chris Mayor.
Date: Friday, October 15
Venue: Stade Aime-Giral
Kick-off: 21.00 (20.00 BST)
Referee: Nigel Owens (Wales)
Assistant referees: David Bodily (Wales), Hugh Watkins (Wales)
Television match official: Derek Bevan (Wales)