Ospreys remain top of the GUINNESS PRO12 despite going down to a 22-10 defeat at the hands of Scarlets, with all four teams at the top of the league losing in round 12. Ospreys, who hit the GUINNESS PRO12 summit over the New Year, missed the chance to extend their lead with a lacklustre performance by their standards – although Scarlets did exceptionally well to frustrate their guests at the Parc y Scarlets. Priestland was inconsistent with the boot but still managed four penalties, and played a big part in setting up Liam Williams for his first-half try. Williams was again involved when John Barclay gave the Scarlets the perfect start to the second half, and despite Dan Evans’ score with 12 minutes left Ospreys had no answer to the home side’s dogged defence. Scarlets drew the first blood in the game with an early Priestland penalty sailing through the posts. But the home side were soon pegged back on ten minutes when skipper Scott Williams was shown a yellow card for a high tackle on Scott Baldwin. And the Ospreys made use of the advantage immediately as Dan Biggar brought them level with a penalty of his own when Scarlets were penalised for hands in the ruck in their own 22 with 14 minutes played. Priestland missed a chance to move the Llanelli outfit ahead while they were still a man down, his second penalty attempt drifting wide of the posts, but made no mistake with another on 24 minutes once Williams had returned to the fray. Scarlets were well on top and looking like causing an upset, and on the half hour they made the key breakthrough, Liam Williams spectacularly diving over with a celebration to match after Priestland had made the space. The fly-half could not add the extras however, and Scarlets were denied a second score just four minutes later when Aled Davies’ try was ruled out for a knock-on as he crossed the line. But there was still time for Priestland to slot another kick through with just two minutes left in the half to make it 14-3 at the break with Scarlets looking comfortable. The home side did not let up and made a sensational start to the second-half with Liam Williams once again at the centre of the action, feeding Barclay to finish the try after Scott Williams made a huge break from Scarlets’ own half on 42 minutes. The clock was now well and truly on Scarlets’ side, and consistent mistakes at the breakdown cost the Ospreys dear. The game got scrappier as Scarlets tried to keep the ball, and tempers started to rise as Ospreys became increasingly frustrated, conceding yet another penalty on 55 minutes for Priestland to sweep over. But something had to give and Ospreys finally forced the breakthrough after 66 minutes, Evans showing incredible strength to shrug off two players and twist his way over the tryline to put Ospreys back in the game. Biggar sneaked the conversion inside the right post to reduce the deficit to 12 points with as many minutes left to play. Ospreys continued to see plenty of the ball, but the execution was not there all evening and they could make no further impression on the scoreboard as they slipped to their first defeat to Welsh opposition in 18 derbies. Meanwhile Scarlets leapfrogged Edinburgh into seventh in the GUINNESS PRO12 and have now lost just once at home in their last 15 in all competitions. Follow us on Facebook, join the conversation on Twitter, sign up to our YouTube channel for extensive match highlights and sign up for our newsletter for regular updates on the GUINNESS PRO12