The Ospreys took a big step towards Heineken Cup quarter-final qualification on Friday with a hard-fought 16-8 win over an ill-disciplined Ulster team at Ravenhill.
Should the Ospreys beat Gloucester at home in what is sure to be a pool decider, and then beat Bourgoin, they ought to book themselves a place as best runners-up even if Gloucester trump them on accrued bonus points.
Ulster's chances are now nil, and they have only themselves to blame.
But the locals will have been buoyed by this performance. Yes, it was yet another defeat, but it was a far cry from last week's 48-17 defeat in Swansea.
Egged on by the spirited crowd, they made a lively start to the game, with Tommy Bowe shaking the Ospreys with a splendid break out of defence.
The visitors' problems then began to mount as passes went to ground and touch-finders failed to die.
Despite the errors, the Ospreys still had the lion's share of territory and it was James Hook opened the scoring in the 11th minute of the game after Ulster were penalised for not releasing, and he put over a second penalty moments later as Neil Best was pinged for coming in at the side of a ruck.
Niall O'Connor answered back with three points of his own as the Welsh infringed at the re-start.
The storm of points was followed by a long passage of attritional play that saw Ulster eke out more territory and possession.
Then, on the stoke of half-time, Ulster stole the lead with a beautiful try by Simon Danielli. Shane Williams over-committed himself in defence and the big Scotsman got past him before collecting a pass and sprinting to the corner from forty yards out.
There was still time for Hook to have another dab at goal form off the tee but his long-range kick at goal didn't have the legs, and Ulster went to the break nursing a slender 8-6 lead.
The Ospreys exploded into the second half with Hook and Justin Marshall attempting to weave their magic on attack. But the Ospreys still weren't rid of the elementary errors and a golden opportunity for Lee Byrne was soon butchered by a forward pass.
Just as the crowd began to wonder whether their run of bad luck was at an end, the Ospreys struck with a piece of first-phase genius.
Filo Tiatia collect the ball at the tail of a line-out just inside Ulster's 10-metre line and feed Marshall coming through the middle. It was a simple move but perfectly executed - not a finger touched the former New Zealand star as he galloped home to take the lead with a converted try.
Things then went from bad to worse for the locals as Ryan Caldwell was sin-binned for killing the ball. Hook booted the ensuing penalty between the uprights and suddenly Ulster were eight points adrift.
As he had in the first half, Bowe then fanned Ulster's flames with a brilliant break from his own. But, again, the good work was undone by a yellow card, this one shown to Carlo Del Fava after a pathetic piece of hair-pulling on Adam Jones.
Buoyed by the extra man, the Ospreys set their minds to notching up the bonus point, but Ulster dug deep to keep the scoreline respectable. It was another loss, but the partisan crowd can take heart from the rediscovery of some backbone.
Man of the Match: Tommy Bowe, Simon Danielli and Rory Best all impressed for Ulster, but it was Justin Marshall's grim determination in the third quarter of the game that turned the tables on the Welsh. The former New Zealand scrum-half has still got it - in spades.
For the Ospreys:
Pens: Hook 3
Yellow cards: Caldwell (54, Ulster, not rolling away), Del Fava (66, Ulster, hair-pulling)
Ulster: 15 Bryn Cunningham, 14 Tommy Bowe, 13 Andrew Trimble, 12 Rob Dewey, 11 Simon Danielli, 10 Niall O'Connor, 9 Kieran Campbell, 8 Matt McCullough, 7 Kieron Dawson, 6 Neil Best, 5 Ryan Caldwell, 4 Justin Harrison, 3 Declan Fitzpatrick, 2 Rory Best (c), 1 Bryan Young.
Replacements: 16 Tom Court, 17 Matt Miles, 18 Carlo Del Fava, 19 David Pollock, 20 Issac Boss, 21 Paddy Wallace, 22 Mark McCrae.
Ospreys: 15 Lee Byrne, 14 Nikki Walker, 13 Mark Taylor, 12 Sonny Parker, 11 Shane Williams, 10 James Hook, 9 Justin Marshall, 8 Filo Tiatia (c), 7 Marty Holah, 6 Jonathan Thomas, 5 Ian Evans, 4 Alun Wyn Jones, 3 Adam Jones, 2 Huw Bennett, 1 Duncan Jones.
Replacements:16 Richard Hibbard, 17 Paul James, 18 Ian Gough, 19 Hale T-Pole, 20 Mike Phillips, 21 Shaun Connor, 22 Andrew Bishop.
Referee: Malcolm Changleng (Scotland)
Touch judges: Rob Dickson (Scotland), Jim Yuille (Scotland)
Assessor: Brian Campsall (Wales)
Television match official: GÃ©rard Borreani (France)