The Ospreys held on for a 22-19 win over Cardiff Blues in Friday's Welsh derby, a result that pushes them into the RaboDirect PRO12 play-off places.
Both Welsh rivals headed into this match on the back of a win. Cardiff had emerged narrow victors at Glasgow, while Ospreys had overcome Castres. And the early exchanges suggested there'd be little between the two teams in wet and windy conditions at Cardiff Arms Park.
The deadlock was broken in the third minute, when Leigh Halfpenny capitalised on indiscipline from the visitors to kick his side in front.
But Ospreys quickly hit back, and they were in front after 11 minutes following a brace of penalty goals from Dan Biggar.
Biggar struck a third penalty goal on 22 minutes to put his side further in the lead, but the Blues hit back just ahead of the half hour with the game's first converted try. Kristian Dacey crossed after the hosts had built pressure in attack, with the TMO confirming the try for Halfpenny to convert.
It remained 10-9 to Cardiff until the dying minutes of the half, when another quick-fire brace from Biggar punished home indiscipline and put his side back in front.
Halfpenny's penalty goal early in the second-half put his side within two points, but Ospreys struck the killer blow soon after. Justin Tipuric showed his class with Ospreys first try, which Biggar converted to give the visitors a lead they would defend for the remainder of the game.
The most Cardiff could muster was two penalties kicked by Halfpenny around the hour, but they were unable to breach the Ospreys line for the pivotal score that could have won them the game.
For Cardiff Blues:
Pen: Halfpenny 4
Pen: Biggar 4
Cardiff Blues: 15 Leigh Halfpenny, 14 Alex Cuthbert, 13 Richard Smith, 12 Dafydd Hewitt, 11 Harry Robinson, 10 Gareth Davies, 9 Lloyd Williams, 8 Robin Copeland, 7 Rory Watts-Jones, 6 Andries Pretorius, 5 Filo Paulo, 4 Macauley Cook, 3 Benoit Bourrust, 2 Kristian Dacey, 1 Sam Hobbs (c).
Replacements: 16 Rhys Williams, 17 Thomas Davies, 18 Scott Andrews, 19 James Down, 20 Josh Navidi, 21 Lewis Jones, 22 Gavin Evans, 23 Chris Czekaj.
Ospreys: 15 Sam Davies, 14 Hanno Dirksen, 13 Tom Isaacs, 12 Ben John, 11 Aisea Natoga, 10 Dan Biggar, 9 Tom Habberfield, 8 Joe Bearman, 7 Justin Tipuric, 6 Sam Lewis, 5 James King, 4 Alun Wyn Jones (c), 3 Adam Jones, 2 Scott Baldwin, 1 Ryan Bevington.
Replacements: 16 Matthew Dwyer, 17 Marc Thomas, 18 Dan Suter, 19 Morgan Allen, 20 Tyler Ardron, 21 Tito Tebaldi, 22 Ashley Beck, 23 Jeff Hassler.
Referee: Jérôme Garcès (France)
Assistant referees: Rhys Thomas (Wales), Sean Brickell (Wales)
Television match official: Gareth Simmonds (Wales)