Dan Biggar kicked six from six at the Liberty Stadium on Saturday evening but was unable to guide the Ospreys to derby victory as they had to settle for a losing bonus point against the Scarlets.
Having taken a 9-0 lead into the break the Ospreys were pegged back in the second half but still led 15-12 at the hour mark. However, last season’s PRO12 champions were able to take the lead in the final quarter, eventually outscoring the hosts three tries to none.
With a raucous atmosphere greeting the two teams as they ran out, passions were running high in the opening minutes.
A frantic phase of play early on saw the Ospreys pressing, James Hook almost getting Jeff Hassler away on the Scarlets 10m line, only for the ball to go to ground and Rhys Patchell to launch a stunning counter up the right, linking up with Gareth Davies who pinned his ears back to go for the corner only to be denied by a great cover tackle from Dan Evans, who had tracked back across the field.
After that early scare the game settled into a pattern that saw the Ospreys playing with a physicality and directness that the visitors were finding difficult to deal with and it almost led to a first try 13 minutes in.
Powerful carries from the likes of Bradley Davies, Olly Cracknell and Kieron Fonotia took the host close to the Scarlets line but when it was moved wide Cory Allen was unable to hold on as he looked to find his way over from five metres out.
From the resulting scrum the Scarlets were always struggling to clear their lines and after Hadleigh Parkes was held up inside the 22, Will Boyde was penalised for taking out Dan Biggar, the fly half picking himself up to slot over the three-pointer.
Five minutes later, Patchell was way off target with a kick from half way after Dan Lydiate was penalised for an obstruction.
A scrum penalty on half way then allowed Biggar to put the Ospreys deep inside the Scarlets 22 and they almost got instant rewards, a series of pick and go’s seeing Nicky Smith driving over the line from close range. Following a lengthy consultation between ref and TMO the verdict was no try, held-up.
However, play was taken back for an Ospreys penalty and they turned down three kickable points to go for the corner. This time, although they again went close, Smith lost the ball forward as he went for the line.
With tensions building, the game erupted just after the half hour mark when both sets of players went at each other for a prolonged period, the outcome of which was a yellow card for Scarlets number eight Tadgh Beirne.
Within a couple of minutes the Ospreys Biggar had doubled the lead, a penalty on the right putting the team six ahead with 35 minutes played.
The Scarlets should really have replied instantly, an Ospreys offside from the restart giving Patchell a shot at the posts that he pulled horribly wide.
Instead, the lead was nine points at the break, Biggar with his third penalty, the Scarlets going off their feet after a great break up the left from Rhys Webb and Jeff Hassler had taken the Ospreys 40m upfield.
HALF-TIME: OSPREYS 9-0 SCARLETS
Having dominated the first period without conceding any points, the Ospreys were underneath their own posts within 150 seconds of the restart as Gareth Davies rounded off a counter attack from halfway to hold off James King and score.
However, celebrations were temporarily put on hold when it was referred upstairs for a knock-on by Samson Lee that looked pretty clear but the officials clearly felt that advantage had been played and awarded the try despite the protests from the home crowd.
Patchell wasn’t enjoying a good night from the tee though and he was off target again with the conversion attempt.
His opposite number was certainly enjoying a more profitable evening and after Aaron Shingler was penalised for not releasing, Biggar made no mistake as he slotted his fourth successful kick over from 40m out .
The contest then took a dramatic turn as the Scarlets drew level, scrum half Davies going over for his second, taking the pass off Parkes to race clear from 20m before Patchell finally got one on target.
It was on a knife edge and you could feel the tension in the air as the Ospreys pressed again from a lineout, Fonotia and Smith both carrying at the heart of the Scarlets defence before an offence on the ground in front of the posts gave Biggar the easiest of three points to put his team back in front.
There was drama and confusion around the hour mark as, first, the Scarlets thought they’d snatched the lead as Wyn Jones looked to drive over from close range only for the TMO to spot that he had been stopped short.
To the Ospreys frustration, play was brought back for an earlier offence and Dmitri Arhip, minutes into his return to action for his first PRO14 appearance of the season, was sent to the bin for collapsing the maul.
The Scarlets looked to power over again and with the Ospreys pack a man light there was no stopping the visitors this time, Lee dotting down and Patchell converting to put them four ahead.
At the other end Patchell then played himself into trouble trying to play the ball out, with the Ospreys eventually winning a penalty for offside and Biggar was on target for the sixth time, reducing the deficit to a point.
Confusion reigned again when the TMO was called to rule on a potential Scarlets fourth try, David Bulbring held up, but play was actually taken back for an Ospreys penalty, 30m upfield, Steff Evans offside.
An Ospreys offside on the 22 then allowed Rhys Jones to go for the posts to stretch the lead back up to four but he pushed it across the face of the posts and wide.
The final minutes were played out inside the home 22 as the Scarlets looked to kill the game off and, possibly, claim a fourth try, but there was no change to the score as the Ospreys losing run continued.