After completing the double against the Scarlets last season, the Ospreys kept their grip on the Evening Post Cup this afternoon with their third straight win against their local rivals, at a sold-out Parc y Scarlets.

A charged up crowd gave a huge welcome to the two sides, and it was the home team, with their supporters roaring them on, who came out all guns blazing. They were handed opportunity to take the lead with less than three minutes gone when Andrew Bishop failed to roll away after the tackle, but Stephen Jones skewed a kickable penalty to the left of the posts.

It was a typically fiery opening to a West Wales derby, and referee Nigel Owens called the two captains together in only the 5th minute after a dust-up after Ricky Januarie was penalised for not releasing, the upshot of which saw Jones giving the home side the first score of the afternoon with a penalty that took him to second in the all-time list of Scarlets point scorers, moving ahead of Phil Bennett.

In a frantic opening with possession switching sides constantly and hard hitting tackles on either sides, there was very little in the way of quality rugby but plenty happening, on and off the ball, to keep the capacity crowd on the edge of their seats as the teams wrestled for superiority.

As the midway point of the first half approached, Dan Biggar was handed the opportunity to level scores after Jonathan Edwards was penalised for not rolling away, but his long-range effort from halfway just faded at the last moment.

The Ospreys took the lead with 27 minutes on the clock from the unlikeliest of sources, as Paul James crossed for only his 3rd try in his 137th Ospreys appearance. The initial chance came when the Scarlets defence failed to deal with a hopeful Biggar up and under, and after Bishop had gathered the loose ball, Tommy Bowe made a great burst through the Scarlets defence before feeding Biggar who sidestepped Martin Roberts tackle, only to see his final pass for the supporting Bowe knocked into touch by Stephen Jones. From the resulting lineout, James picked up Holah's tap down and charged over from close range. Biggar converted to put the Ospreys 7-3 ahead, but the instant response from the home side saw fullback Rhys Priestland add three points from halfway after Januarie had given away a penalty.

Passions were, if anything, boiling up even hotter as a number of incidents across the pitch went unpunished or undetected as the action continued unabated. With half-time approaching, the Ospreys were forced into two changes, Adam Jones replacing Craig Mitchell in the front row, while James Hook, making his first start in two months, was forced off with an injury picked up during the early stages, Sonny Parker entering the fray.

With the clocking showing 40 minutes, the Scarlets edged back in front after Mr Owens adjudged that fullback Gareth Owen had deliberately knocked on to prevent a try scoring opportunity. The initial impetus came from Sean Lamont who went on a powerful run through the middle, and centre partner Jonathan Davies followed up his good work. Owen looked to have made a good tackle on the Welsh international on the Ospreys 22, dislodging the ball through the force of his tackle but the referee thought otherwise, and Stephen Jones slotted an easy kick over to make it 9-7 at the break.

HALF-TIME: SCARLETS 9 OSPREYS 7

The Ospreys got the second half to a flying start, with their second try of the match, and incredibly, it was prop Paul James who got his own second of the game, after scoring just the two in his previous 136 matches for the region.

It all stemmed from an Ospreys penalty that Biggar kicked to touch, and from the lineout, the ball was spread right across the width of the field. The men in black pounded on the Scarlets line, sucking in defenders, before Biggar spotted an overlap and fed a long ball out wide to James, lurking near the touchline, who went over for the try.

Alun-Wyn Jones became the third Osprey to leave the field, replaced by Jonathan Thomas, before Lee Byrne returned to action after two months out, in place of Gareth Owen, with Richard Hibbard taking the place of Huw Bennett.

Biggar spurned the chance to extend the lead, his penalty from halfway going well wide, but he was given an immediate chance to make amends as the referee immediately awarded the Ospreys another penalty, giving Martin Roberts a long talking to, presumably for something he said, and Biggar duly slotted over from the 10 metre line to make it 15-9 much to the annoyance of the home support.

Biggar's excellent tactical kicking was ensuring that the Ospreys maintained the upper hand, with the back row also working well as a unit, while the presence of Adam Jones in the scrum was clearly having a positive impact. Another Biggar penalty just after the hour following an offence in the ruck extended the lead to nine points.

The Ospreys were then forced to absorb a period of extensive Scarlets pressure as they looked for a crucial score. Home skipper David Lyons led the charge by example, ably supported by Vernon Cooper, but the ball went astray at the death. However, the home side kept up the pressure, and after being awarded a kickable penalty, they opted instead to take the line-out. The ball was moved well across the line, before the Scarlets launched charge after charge on the Ospreys line, all of which were repelled by an outstanding defensive effort, only for the referee to call the game back for an offence by Ian Gough at the original lineout, some two minutes earlier. Again, waves of Scarlet pressure tested the Ospreys defence, with Nikki Walker making a crucial tackle on the line to prevent a score, before Januarie was finally able to clear the danger with a long kick to touch.

It was the Ospreys voices that were now soaring in the stands, and having soaked up everything the home side could throw at them, Biggar's third successful penalty of the second half, and his fourth kick of the day, made it 21-9 with four minutes remaining.

The home side did finally get their try with the game in stoppage time, Roberts taking a quick tap penalty in the Ospreys 22 to release Johnathan Edwards, and there was no stopping the flanker from short range. The conversion was missed, Nigel Owens blew for time and the Ospreys players, supporters and management celebrated an unbeaten December, with four wins from four, that has seen the side move to the top of the Magners League, albeit potentially for just a few hours.