The Ospreys came out comfortably on top in the battle of the 100 per centers at the Liberty Stadium on Sunday afternoon, ending Ulster's unbeaten record to the season while stretching their own record to four wins in four games.
Dan Biggar once again proved influential, kicking 20 points to take his personal tally for the season to 67, with the other points coming from a penalty try and a Richard Fussell touchdown, while Matthew Morgan added a late conversion after replacing Biggar towards the end.
The first try of the afternoon came inside 150 seconds, Ulster’s young fly-half Paddy Jackson, a late call-up for the injured Ian Humphreys, spotting a gap in the Ospreys defence to race through from the 22 after some quick recycling work from his pack before picking himself up to add the conversion.
The Ospreys looked to hit straight back and were awarded a penalty after Andy Kyriacou was pinged for not releasing, but Biggar’s long range attempt struck the left hand upright.
A penalty against the Ospreys at the scrum on halfway allowed Jackson a chance to try for the posts but although his effort had the distance it was just off-target.
Pressure from the Ospreys scrum saw the Ulster front row popping up, allowing Biggar to open his team’s account in the 13th minute with a penalty from a central position mid-point between the 10m and 22m lines.
Minutes later Jackson was off target once again following an offside call against Biggar.
The scrum was proving to be something of a lottery and after a dust-up between the two front-rows resulted in an Ulster penalty, Richard Hibbard was sent to the bin less than 20 minutes into his first appearance of the season.
It was proving to be a tight, feisty affair and another Biggar penalty, for not rolling away, brought the Ospreys back to within a point 27 minutes in.
Despite being a man down the Ospreys were enjoying their best period of the game and more Ulster indiscipline allowed Biggar to edge his team in front for the first time just a couple of minutes later, Hibbard returning to the fray with the Ospreys 9-7 ahead.
Good lineout ball then allowed the Ospreys pack to rumble forward towards the Ulster line, the visitors only able to halt their progress illegally, allowing Biggar to slot over another penalty from close to the right hand touchline.
Good covering defence from the Ospreys snuffed out the threat as Craig Gilroy collected a clever cross kick from Jackson, the supporting Dan Tuohy forced into a knock on in the tackle,
With the break approaching Ulster enjoyed a spell of concerted pressure at they looked to wrestle back the lead, Gilroy, Ian Whitten, Chris Henry and Lewis Stevenson all trying unsuccessfully to find their way through a black wall.
HALF-TIME: OSPREYS 12 ULSTER 7
The Ospreys made a bright start to the second half, building up territory through multiple phases with Ian Gough, Hanno Dirksen, Tom Isaacs and James King, on for James Goode, all carrying well. However, with no way through a resolute Ulster defensive line, Biggar attempted to slot over a drop goal but failed to find the target.
A well worked move from a lineout minutes later saw Biggar bursting through the Ulster line into their 22, a desperate last-ditch tackle from Robbie Diack halting his progress. The Ulster number eight was pinged for not rolling away following the tackle and the young fly-half duly slotted over his fifth successful penalty of the afternoon to make it 15-7.
Fussell did exceptionally well to chase and gather a Rhys Webb up and under as the Ospreys looked to take advantage of the extra man, and he almost freed Isaacs, the centre beating two tacklers before stepping in touch as he looked to race away up the line.
Turnover ball allowed Andrew Bishop to kick to the corner for Dirksen to chase, the bounce just beating the South African born youngster, but the Ospreys won the ball back from the resulting lineout to keep the pressure on Ulster. Awarded a scrum just metres from the line, the Ospreys drove forward, winning a penalty and opting to pack down again. Reset on multiple occasions, with the Ulster pack penalised on three separate occasions, the referee eventually issued a warning to the visitors.
However, at the next attempt Ulster were again penalised, but no yellow card appeared. This time though the outcome was inevitable, a penalty try awarded as the Ulster scrum buckled, Biggar adding the extras from right in front of the posts, taking the score to 22-7 in the Ospreys favour. The 21-year old then stretched the lead to 18 points with a straightforward penalty after an Ulster offside.
As the game moved into the final 10 minutes the Ospreys secured the win with their second try, Fussell scoring beneath the sticks after good pressure forced a retreating Ulster into an error, the winger hacking the loose ball clear before winning the race to collect the ball and score, Morgan converting.
Despite the Ospreys dominance Ulster managed to have the final say, a powerful drive towards the line eventually being halted by illegal means, giving referee Dudley Phillips little option but to award a penalty try, the conversion from James McKinney rounding off the scoring.