The Ospreys booked their spot in the Heineken Cup quarter-finals as one of the two best-placed pool runners-up after recording a nervy 28-21 win over Bourgoin at Stade Pierre Rajon on Sunday.
Needing a victory to go progress, Ospreys coach Lyn Jones opted to use former All Black number eight Filo Tiatia as a midfield battering ram, and the ploy yielded two crucial first-half tries.
And while Tiatia was making huge yards with ball in hand, New Zealand-born centre Sonny Parker, playing at the back of the scrum in the set-pieces, produced a copybook defensive display in the second half to keep the home side out.
The win - the Ospreys' first ever in France - earns them a quarter-final away from home in early April.
Jones took no chances with his selections, with all 15 of the starting line-up having Test experience.
An all-Wales front five was backed up by former All Blacks Marty Holah, Tiatia and Justin Marshall, with James Hook and Gavin Henson given the task of putting the likes of Shane Williams into space.
Bourgoin centre Sebastien Laloo and Hook traded penalty goals, but the visitors could not turn possession into points until Hook levelled the scores on the 20-minute mark after Laloo had again put his side ahead.
Tiatia flirted with a yellow card by going too high in a tackle, but made immediate amends by joining the backline and creating the space for Williams to score the game's opening try.
Hook added the extras, and was calling for the kicking tee barely two minutes later as prop Adam Jones and Henson combined to put full-back Lee Byrne over in the corner.
Hook slipped as he attempted the conversion, which missed by a long way, but the Ospreys went into the half-time break with a handy and deserved 18-6 lead.
The Ospreys started the second spell strongly, and English referee Wayne Barnes was not popular among visiting fans when he disallowed a try to Parker because of crossing.
Bourgoin charged down two consecutive clearing kicks from Marshall before they had a try disallowed by the referee.
The home side had better luck five minutes later when they drove the Welsh pack backwards at speed.
Referee Barnes called on the television match official for a ruling and it went in favour of Bourgoin prop Karena Wihongi.
Laloo's conversion attempt was wide, and the Ospreys were clinging to a seven-point lead as the match moved into its final quarter.
Hook coolly slotted a 35-metre penalty goal to ease the nerves, but it needed several crunching tackles from Parker to keep Bourgoin at bay - especially after Byrne was sin-binned for a late shot.
Bourgoin fly-half Morgan Parra narrowed the margin with a penalty goal in the final minutes, but a Henson interception set up replacement back-rower Jonathan Thomas for the match-sealing try.
The home side had the final say of the match when replacement full-back Florian Denos chipped ahead, regathered and scored.
Tries: Wihongi, Denos
Pens: Laloo 2, Parra
For the Ospreys:
Tries: Williams, Byrne, Thomas
Cons: Hook 2
Pens: Hook 3
Bourgoin: 15 Anthony Forest, 14 Matthieu Nicolas, 13 Rudi Coetzee, 12 Sebastien Laloo, 11 Jean-Francois Coux, 10 Morgan Parra, 9 Mickaël Forest, 8 Wessel Jooste, 7 Augusto Petrilli, 6 Julien Frier, 5 Chris Wyatt, 4 Julien Pierre (c), 3 Pablo Cardinali, 2 Jean-Philippe Genevois, 1 Arnaud Tchougong.
Replacements: 16 Karena Wihongi, 17 Olivier Sourgens, 18 Bryce Williams, 19 Brice Monzeglio, 20 Nicolas Carmona, 21 Matias Viazzo, 22 Florian Denos.
Ospreys: 15 Lee Byrne, 14 Nikki Walker, 13 Sonny Parker, 12 Gavin Henson, 11 Shane Williams, 10 James Hook, 9 Justin Marshall, 8 Filo Tiatia, 7 Marty Holah, 6 Ryan Jones (c), 5 Alun-Wyn Jones, 4 Ian Gough, 3 Adam Rhys Jones, 2 Huw Bennett, 1 Duncan Jones.
Replacements: 16 Edward Shervington, 17 Paul James, 18 Ian Evans, 19 Jonathan Thomas, 20 Mike Phillips, 21 Mark Taylor, 22 Jonny Vaughton.
Referee: Wayne Barnes (England)
Touch Judges: Ashley Rowden (England), Paul Dix (England)
Television match official: Geoff Warren (England)