A heavy final day defeat at Parc y Scarlets was a hugely disappointing way to end the regular season, but the Ospreys did enough over 22 games to ensure a place in the end of season play-offs.
The first and last tries went to the Ospreys, Keelan Giles with the first on 12 minutes and Dan Baker at the death, but in between it all went wrong as the Scarlets ran in five of their own on the way to their biggest ever win in this fixture.
Giles’ try was the 14th of his debut season, a tally bettered by only one player, Tommy Bowe, in Ospreys history. That was little solace though for a team well beaten on the day.
It started well enough when Dan Biggar opened the scoring inside two minutes, hitting a straightforward penalty from 25m out on the right after a Scarlets offence at the ruck.
The hosts hit back in style, attacking with pace, going through multiple phases and stretching their opponents enough to create an opening on the left where Ken Owens looked to stretch over in the corner. It was Bradley Davies who got across to put in a last ditch tackle, doing just enough to force Owens into touch before he could ground it.
The Ospreys, however, made a hash of their lineout, losing the ball close to their own line and, although they were able to keep their line intact, a push by Rhys Webb on Rhys Patchell resulted in a Scarlets penalty and Patchell leveled it with five minutes played.
After that frenetic opening spell the Ospreys were able to slow things down and start to play their own game, half breaks by Tom Habberfield and Kieron Fonotia giving them go forward. The pack then took over, pick and drives taking them closer to the line before Biggar slipped a lovely inside pass to Giles who showed impressive strength to get over the line to score despite the presence of Owens, Biggar converting.
Patchell reduced the deficit from right in front of the posts after the Ospreys were pinged for not releasing, the scoreboard reading 6-10 with 18 minutes gone.
Jonathan Davies then, somehow, found his way through a host of defenders to get close to the Ospreys line where he was hauled down, some great work on the floor by Justin Tipuric winning a penalty for his team.
The difference cut to a solitary point when Patchell again split the posts, this time after Rhodri Jones was penalised when the scrum went down.
The Scarlets were controlling things and they received a boost just before the half hour mark when Ospreys skipper, Webb, was shown a yellow for a high tackle on Owens.
The home team looked to take immediate advantage of the extra man and they thought they’d scored immediately after from their next attack. The ball was worked out wide to the left where Johnny McNicholl went over in the corner despite the efforts of Giles.
Scarlets supporters celebrated and Patchell lined up the conversion, but there was a twist when referee Nigel Owens went upstairs and after intense scrutiny the score was ruled out for a Scarlet knock-on at a ruck in the build-up.
There was no let-up as the Scarlets came back again, wave after wave of pressure on the Ospreys line.
Jonathan Davies was hauled down inches short on the left but, with defenders sucked in, there was acres of space on the other wing and when it was worked across the field Will Boyde was left with the simplest of finishes.
Patchell added the extras and with five minutes left in the half the hosts led 16-10.
With Webb waiting on the touchline to return there was still time for the Scarlets to stretch their lead before he returned, Gareth Davies breaking from the back of a scrum almost on his own 22, carrying well over halfway before offloading to Davies. He was stopped by Giles, but Steff Evans finished it off, pinning his ears back and going for the line.
The score was converted again by Patchell, and the hosts held a 13 point lead at the break.
HALF-TIME: SCARLETS 23 OSPREYS 10
The Ospreys, back up to 15, were out early for the second half, no doubt with a rocket in their collective ear, but after a positive start it was the Scarlets who should have got the next points.
Fortunately for the Ospreys, Patchell’s radar was off, missing the penalty after the ref spotted some blocking by Tipuric to create space for Dan Evans as made his way through the midfield.
There was a reshuffle when Biggar limped out of the action, Josh Matavesi moving to outside half as Jonathan Spratt came on, the day after confirming he will retire at the end of the season.
A powerful Scarlets maul was stopped just short of the line, Owens looking to get the ball over the line, before great work from Habberfield saw him not only stealing the ball at the ruck but also winning the penalty to allow Matavesi to clear.
Patchell then spurned another opportunity to stretch the Scarlets lead, his kick just wide after a penalty reversal following a check with the TMO confirmed a no-arms tackle by Bradley Davies.
It was all Scarlets and great work from McNicholl, combining with Aaron Shingler, almost saw the former Crusader going over, the ball knocked forward in contact a metre or so out.
The constant pressure meant the score was inevitable and it came on the hour mark as Liam Williams launched a counter-attack from inside the Scarlets half that ended with Shingler strolling under the posts. Patchell’s conversion meant the hosts led by 20 with as many minutes remaining on the clock.
Habberfield then did exceptionally well to track back and stop Scott Williams as he raced through from halfway for what seemed a certain try, not only hauling him down five metres out but getting straight back to his field to win the penalty.
The Ospreys were struggling to make any headway though and after Paul James got turned over midway inside his own half the visitors were always looking stretched. Davies carried, Steff Evans showed good skill with a pass out the back of his hand, and McNicholl raced up the left flank to score.
With Patchell off the field, Hadleigh Parkes missed the conversion missed but the next Scarlets try came just two minutes later, Davies collecting his own kick then racing through to score try number five, which again went unconverted.
The final score of the game went to the Ospreys, Baker going over from close range following good work by Fonotia, Dan Evans converting. The score made little difference in the end though as they now look to use the two week break to dust themselves down and regroup ahead of their semi-final.