A massive effort from the Ospreys forwards gave their team a gritty win over the Cardiff Blues at the Arms Park and sent the region top of the Magners League for the New Year.
With no fewer than 18 Welsh internationals on display at the Arms Park, the occasion was always going to be a fiery one and it didn't disappoint as many players went out to put one over their direct competitors for international honours.
The Blues made a positive start and turned over the Ospreys after the opening kick-off, allowing Nick Robinson to release his backs before Ospreys skipper Ryan Jones was guilty of not rolling away in the tackle. Kiwi fullback Ben Blair slotted the penalty for an early lead.
Ospreys scrum-half Mike Phillips was heralded by a chorus of boos against his old club as he looked to inject some pace into their first attack before a high tackle from Blues prop Taufa'ao Filise gave Dan Biggar the chance to draw the Ospreys level.
A mistake from Robinson with a short kick-off allowed the Ospreys to assert their weight advantage at scrum-time, with a huge contact on half-way providing an early psychological boost. Another break from Phillips after 10 minutes again gave the Ospreys momentum before the Blues forwards went offside at a ruck on their 22, with Biggar slicing his penalty wide for a let-off for the home-side.
Blair was also guilty of missing a penalty soon after as Jones was again penalised in the tackle area, but the Blues were gifted another opportunity when the Ospreys persisted and were found guilty of killing the ball. Blair was successful this time for a 6-3 lead.
Ospreys fullback Gavin Henson then latched on to some quick ball from a ruck and fed Sonny Parker to burst down the wing. Parker went straight through the tackles of Richard Mustoe and Blair before openside Marty Holah collected a loose ball after a huge hit by Andy Powell on Ryan Jones, and forced the Blues defence to concede a five-metre scrum after a grubber kick found space in behind.
Blair was forced from the field with a suspected broken bone in his hand after his clash with Parker and a series of scrappy exchanges yielded little for either side as the half meandered in the middle stages. Both sets of half-backs found precious little space to put any depth onto the ball, and any prospective attacks were swiftly swallowed by the blitz defences.
A moment of brilliance from Biggar broke the monotony as he chipped the ball away from Blues scrum-half Jason Spice and collected before Phillips sent Bowe through a gap out wide. The Irish wing had only to pop the ball to Lee Byrne for the fullback-cum-wing to crash over in the corner.
Moments later a scintillating break from Leigh Halfpenny shredded the Ospreys defence and after a superb steal from Gavin Henson the Blues were granted a five-metre scrum. With the Ospreys defence set, Robinson sat back in the pocket and slotted a drop-goal to give the Blues the half-time lead.
The second-half sparked into life immediately, with Martyn Williams' kick allowing Tom James to race into Ospreys territory, only for his path to be blocked illegally by Marty Holah. Robinson sliced his penalty attempt horribly, just as James Hook was introduced in place of Biggar.
The early exchanges of the second-half were dogged by handling errors from the Blues, as they were continually guilty of looking for offloads in restricted space.
Blues wing James then injected some pace into proceedings with a storming run from his own 22 as the game approached the hour, only halted by a stunning last-ditch tackle from Byrne. Byrne was guilty of killing the ball as the Blues attempted to recycle, earning himself a yellow card and allowing Robinson to extend the Blues' lead.
James Hook slotted a penalty to bring the Ospreys back to within a point after Blues replacement Darren Allinson was penalised on the floor, before the Blues had further cause for concern as Martyn Williams trudged off with a shoulder injury.
The Blues were unable to capitalise on Byrne's absence, failing to break clear of the mess at the breakdown. It took a moment of magic from Henson, turning the Blues defence with a superb grubber, to create any space only for an excellent cover tackle by Halfpenny to snuff out the danger.
The Blues were in further trouble moments later after some excellent footwork by Hook, who released Byrne towards the line only for him to knock on. Some fine work by the Ospreys back-row allowed Blues No.8 Powell no space at the base of a scrum after more handling errors, and the Ospreys signalled for the five-metre scrum when Powell was pinged for holding on.
After several patient phases from the forwards, a superb wide pass from Hook found Filo Tiatia in space with only Mustoe between the veteran All Black and the line, and he charged over for the killer score.
Ospreys coach Sean Holley praised his side's attacking intent and perseverance in breaking down a stout Blues side. "The score-line was close because perhaps we didn't take as many chances but the difference really was the relentless pressure and some of the attacking rugby we took to the Blues," he told BBC Wales. "We were rewarded with two good tries and we deserved it but for long periods we were frustrated by some very good Blues defence.
"The intensity was awesome and it gives me goose bumps reflecting and both teams know they've been in a huge game.
Holley enjoyed the atmosphere and hoped that the fans went away happy. "They were passionate about winning the game, I'm hoping the crowd have gone away after enjoying a great Welsh derby because that's what we're here to do as rugby is an entertainment business.
"The league table is a satisfying sight but there is still a long way to go but we've got to be confident because we are in a good position."
Blues coach Dai Young admitted that his side didn't do enough to deserve victory at the Arms Park. "Obviously we were playing a quality team, it was always going to be tight and it could have gone either way but I have to be honest, they did deserve it," he told BBC Wales. "They edged it, the scrum was a problem for us and I don't think we were accurate enough with the ball.
"We were not in a position to mount enough pressure with the ball in their half and they controlled the game better than we did."
Blues: Ben Blair; Richard Mustoe, Tom Shanklin, Gareth Thomas, Tom James; Nicky Robinson, Jason Spice; Gethin Jenkins, Gareth Williams, Taufa'ao Filise, Deiniol Jones, Paul Tito (capt), Maama Molitika, Martyn Williams, Andy Powell.
Replacements: John Yapp, T Rhys Thomas, Scott Morgan, Robin Sowden Taylor, Darren Allinson, Ceri Sweeney, Leigh Halfpenny.
Ospreys: Gavin Henson; Tommy Bowe, Sonny Parker, Andrew Bishop, Lee Byrne; Dan Biggar, Mike Phillips, Paul James, Richard Hibbard, Adam Jones, Ian Gough, Alun Wyn Jones, Ryan Jones (capt), Marty Holah, Filo Tiatia.
Replacements: Ed Shervington, Cai Griffiths, Jonathan Thomas, Tom Smith, Jamie Nutbrown, James Hook, Jonny Vaughton.
Referee: Nigel Owens (WRU)