Northampton have to take maximum points away from Sunday's clash against the Ospreys if they want to progress in this year's Heineken Cup.
After being torn limb from limb at home to Leinster at Franklin's Gardens, the success in Dublin the following Saturday was from another planet.
Saints possess a number of fleet-footed attackers but it's their power game that is so impressive. Big men including Samu Manoa, Courtney Lawes, Tom Wood and Luther Burrell in the backs all carry hard and consistently make ground. They also suck in defenders, which caused Leinster to work tirelessly at the Aviva Stadium to the point of sheer exhaustion. Victories such as that one are more satisfying than walkovers, no question, especially after Northampton's humiliation the week before.
The early damage to Northampton's hopes for this season in Europe however looks irreversible, unless they take maximum points from their trip to Swansea and do the same again when they will host a disinterested Castres in the final round. That and hoping for a slip up from Leinster, who lead Pool 1 by four points, could give them a chance. As things stand, three teams - the Blues, Saracens and Leicester - are better placed to qualify as a best runner-up.
The Ospreys meanwhile, for no lack of effort, have just lacked the quality of their counterparts in their group.
Ten points off the pace against Leinster and eleven behind Saints when they played at Franklin's Gardens, that's a sizeable gap behind two of Europe's strongest teams.
Defeating a strong Castres team at home is definitely a feather in the cap - they are Top 14 champions after all - but the Ospreys lack enough penetration in the backs to truly worry better teams. Aisea Natoga does look lively on one wing but the threatening Ospreys of yesteryear, including Shane Williams and Tommy Bowe, are now long gone.
Dan Biggar remains an excellent goal kicker and the main source of his side's points at fly-half behind a very experienced pack led by Alun-Wyn Jones. But Northampton have a set of forwards strong enough to overcome what the Ospreys will throw at them on Sunday, regardless of being on the road.
Biggar lines up alongside Rhys Webb behind a strong looking pack, despite the fact tighthead Adam Jones must make do with a place on the replacements bench.
"Sunday is going to be a massive game," said head coach Steve Tandy.
"There's a big, typically English team, who are flying high in the league and Europe, coming to the Liberty and both teams need the win, so it's going to be explosive and physical. I'm sure it'll be a great contest."
Northampton meanwhile go for former Osprey Kahn Fotuali'i at scrum-time ahead of Lee Dickson as they look to keep alive their hopes of making the quarter-finals.
Dylan Hartley captains the side while George North is on the left wing and will go up against Canadian international Jeff Hassler at the Liberty Stadium in Swansea.
Ospreys: 15 Richard Fussell, 14 Jeff Hassler, 13 Tom Isaacs, 12 Ashley Beck, 11 Aisea Natoga, 10 Dan Biggar, 9 Rhys Webb, 8 Joe Bearman, 7 Justin Tipuric, 6 Sam Lewis, 5 Ian Evans, 4 Alun Wyn Jones (capt), 3 Aaron Jarvis, 2 Richard Hibbard, 1 Ryan Bevington.
Replacements: 16 Scott Baldwin, 17 Duncan Jones, 18 Adam Jones, 19 James King, 20 Morgan Allen, 21 Tom Habberfield, 22 Sam Davies, 23 Jonathan Spratt.
Northampton: 15 Tom Collins, 14 Jamie Elliott, 13 George Pisi, 12 Luther Burrell, 11 George North, 10 Steve Myler, 9 Kahn Fotuali'i, 8 Samu Manoa, 7 Tom Wood, 6 Calum Clark, 5 Christian Day, 4 Courtney Lawes, 3 Salesi Ma'afu, 2 Dylan Hartley (capt), 1 Alex Waller.
Replacements: 16 Mikey Haywood, 17 Ethan Waller, 18 Tom Mercey, 19 Sam Dickinson, 20 Phil Dowson, 21 Lee Dickson, 22 Glenn Dickson, 23 Fa'atoina Autagavaia.
Date: Sunday, January 13
Kick-off: 12:45 GMT
Venue: Liberty Stadium
Referee: Pascal Gauzère (France)
Assistant referees: Patrick Pechambert (France), Jean-Luc Rebollal (France)
Television match official: Gilles Cogne (France)