the Ospreys came back from 19-11 down after an hour to score 17 unanswered points, including tries for Shane Williams and Lee Byrne, to keep their Magners title hopes intact.
The Ospreys were helped that they could unload a replacements bench including five internationals, which in the end was the difference between the sides.
The Scarlets; cause was not helped in that they were forced into some late changes. They lost most significantly, captain for the day Stephen Jones due to a hamstring injury.
Mark Jones took over as skipper, while Rhys Priestland moved up to out-half.
After the opening minutes turned into something of a cagey arm wrestle, the Ospreys opened the scoring with a Dan Biggar penalty on 19 minutes after Vernon Cooper had encroached offside at a ruck.
But within two minutes the Scarlets were back level through a long range Priestland effort when Cai Griffiths failed to move away after a tackle.
Priestland made it 6-3 with another accurate penalty kick five minutes later after the Ospreys had erred offside
The first try looked on when Williams sent Sonny Parker on a run up the right but he could not get his pass away to Tommy Bowe outside him.
More Ospreys pressure should have helped them to level the scores at 6-6 but Biggar missed a penalty from right in front of the posts.
Priestland was also wayward with a much more difficult penalty kick before he planted two more in first half injury-time to give the Scarlets a 12-3 interval lead.
Ryan Jones’ frustrations with the match officials eased after the break as he scored the opening try of the game on 45 minutes, going in at the left corner from a Williams pass after the Ospreys stepped up the pressure.
The visitors’ hopes of further eating away at the Scarlets’ lead were dashed when James Hook, who replaced the injured Parker at half-time, was well wide with a penalty goal shot.
But Biggar made up for the miss with a penalty on 51 minutes to cut the home side’s lead to a point, just a couple of minutes after Lee Byrne entered the fray for his first action since the RBS 6 Nations.
The Ospreys’ comeback, however, was stopped in its tracks by a try from centre Jon Davies, a score that was made by Daniel Evans, who caught his own up-and-under and jinked his way to a metre from the line.
The visitors did not help their own cause as they kept missing kicks. Biggar and Hook were both off target meaning they had missed four penalties and a conversion.
Hook’s miss came after Scarlets prop Deacon Manu was sin-binned for an off-the-ball shoulder charge.
And with the Scarlets down to 14 men, the Ospreys turned the screw to score two converted tries and a penalty to go into the lead.
First Mike Phillips put Williams haring down the left before Hook broke through midfield and sent Byrne across the line.
Hook’s penalty on 71 minutes gave the Ospreys a nine-point advantage and they held firm for a win that keeps their title challenge alive. There was further disappointment for the Scarlets when Priestland missed an injury-time penalty from the 22.
Scarlets V
