The Ospreys ran four second half tries past their Welsh rivals, the Newport Gwent Dragons, to finish the league phase with a bonus point win which sets up a home semi-final for them in Swansea.
Hampered by injuries, the Newport Gwent Dragons succumbed to a wave of second half attacks from the Ospreys as captain Ryan Jones, fly-half Dan Biggar and replacement duo Nikki Walker and Ryan Bevington helped themselves to tries.
It was a business-like performance from the Ospreys who are coming into form at just the right time.
This was their eighth successive home win in all competition and they will be formidable opponents for whoever visits them at this venue in next Friday’s semi-final (kick-off 7.05pm).
Speaking after the game, centre and man-of-the-match James Hook said: "I think we’re all generally pleased with the way it went but if we are being honest about it, we should have scored a few more tries.
"Obviously there was a touch of nerves, we wanted to be able to run with the ball and look to score tries. They were doing a good job at frustrating us, but we stuck to the game-plan and did what we had to at the end of the day.
"We weren’t really aware of what was going on at the Scarlets, you can’t worry about that, it was in our own hands so we knew what we had to do, regardless of the score there. We took care of it on the pitch.
"The pack were awesome, they did a massive job for us and gave us plenty of ball to get on the front foot which is great for the likes of myself, Tommy (Bowe), Shane (Williams) and Nikki.
"The last two games have been massive for us, beating Munster away and then this win tonight, we’ve showed that we can win big games and we can play in any conditions.
"Next week now, hopefully we’ll get a big crowd, we need a good crowd behind us to help us keep the season alive until the final."
With fellow semi-finalists Glasgow Warriors securing a bonus point at the Scarlets, the Ospreys needed a five-point return to keep ahead of the Scottish side in the standings and they delivered with a powerful second half surge.
The Dragons, who have never won on Ospreys soil, came into this game having beaten their Welsh rivals in the sides’ previous two meetings this season, including a 40-19 LV- Cup success.
But their coach Paul Turner was without 14 regulars for this round 18 date as he asked young players like Adam Hughes (20), Aaron Coundley (19) and Lewis Evans (22) to ‘front up’ and meet the physical challenge from the Ospreys.
To their credit, the men of Gwent hung in there in the first half, restricting the Ospreys to just one try – a penalty try in the 17th minute after a series of reset scrums.
Their cause was hardly helped by flanker Gavin Thomas’ withdrawal from the side just before kick-off. James Harris deputised in his place.
It looked ominous in the opening quarter as the Ospreys, boasting 15 full internationals, put width on the ball and showed plenty of forward grunt.
Biggar kicked the home side ahead with penalty goals after 6 and 8 minutes, and Dragons full-back Will Harries did well to bundle Ospreys winger Shane Williams into touch as he raided towards the right corner.
The Dragons remained pinned back in that corner, however, and the home forwards carved out the opening try as they put pressure on at scrum-time and following the third five-metre scrum, referee Nigel Owens awarded a penalty try.
Biggar kicked the conversion and swapped penalties with Dragons number 10 Jason Tovey. The remainder of the opening half was of poor quality, with Turner’s side able to soak up the pressure and the Ospreys putting in some aimless kicks.
16-3 ahead at half-time, they tried the more direct route on the restart, and their much heavier pack used their weight advantage to help Jones get over the try-line in the 49th minute.
Jones controlled the ball at the base of an advancing scrum and bided his time before plunging over the whitewash.
The try, converted by Biggar, came after Robert Sidoli had stopped a Tommy Bowe-led attack and full-back Lee Byrne had agonisingly lost control of the ball as he shipped a tackle close to the line.
The Ospreys were missing scoring chances and the Dragons hit back, nothing their one and only try as scrum half Wayne Evans nipped over off the base of a ruck, for Tovey to convert.
On the hour mark, the Dragons’ spirited efforts took a significant hit when young prop Coundley was yellow carded for dropping a scrum and the Ospreys added twelve points to their tally during the sin-bin period.
As space began to open up at both ends of the piece, the Ospreys grabbed try number three. A quick counter attack, which saw lock Jonathan Thomas provide the biggest incision, ended with some deft hands from props Paul James and Adam Jones putting Biggar through for a simple run-in.
With the soon-to-be-retired Filo Tiatia entering the fray, the Ospreys soon had the bonus point in the bag.
Some quick-witted attacking from Mike Phillips and Hook led to replacement winger Nikki Walker getting over for the all-important try, with Biggar’s conversion making it 35-10.
The busy Rhodri-Gomer Davies powered his way through a tackle to get the Dragons without scoring range and a swift surge almost resulted in a try in the left corner. Winger Richard Fussell also found space on the right to threaten with ball in hand, but the Ospreys defence stood firm.
Notably, the Dragons got a glimpse of the future when the 17-year-old Jonathan Evans came on to make his regional debut as a replacement scrum half.
Another replacement, Ryan Bevington, capped off the home win with his first try at senior level, running a good support line to cut through the tiring Dragons defence and defy Harries in the left corner, after an initial break by Williams.