It was Ulster who started the brightest, enjoying the early possession and territory without threatening the line, but the Ospreys burst into life 6 minutes in, Rhys Webb's perfectly weighted box kick giving Dirksen something to chase. The young wing did extremely well to gather under pressure from Mike Allen in the Ulster 22, sparking quick hands in the backs, but Ulster were alert to the danger, snuffing out the combined threat of Richard Fussell and Tom Isaacs on the opposite wing.

That flurry aside, the opening quarter was largely being played out in midfield with neither side able to take control, the first attempt on goal coming in the 22^nd minute after Tom Isaacs was caught in front of the kicker but Ulster fly-half Niall O'Connor was off target from close to the right touchline.

Just a minute or so later the Ospreys were in front, some great opportunism from Dirksen seeing him cross for his first touchdown of the new season. Having secured their lineout ball close to the Ulster 22, the Ospreys backs looked to spread it but miscommunication between the centres saw the ball going to ground. It was Dirksen who reacted quickest, scooping up the loose ball and barging through the Ulster defence to score, Matthew Morgan converting.

As the clock moved past the half hour mark O'Connor got the scoreboard moving for the visitors with a long range penalty after hands in the ruck from Justin Tipuric.

It was a tight, close fought contest with chances at a premium which is why O'Connor opted to go for the posts from inside his own half in the final minute of the first period but he had neither the length nor the direction to trouble the scorers, allowing the Ospreys to head down the tunnel four points to the good.

HALF-TIME: OSPREYS 7 ULSTER 3

An early penalty against James King at the breakdown allowed O'Connor another chance to reduce the deficit, this time from the Ospreys 10m line, but his effort was always drifting wide of the right hand stick.

Morgan responded by slotting over a straightforward from in front of the posts to make it 10-3 after Declan Fitzpatrick was pinged for collapsing the scrum.

Another scrum penalty, on halfway this time, allowed Morgan to take his team up the 22. Richard Hibbard found Jonathan Thomas in the line and as the pack looked to set itself and rumble forward Ulster were guilty of illegally collapsing the maul, Morgan slotting over his third kick of the night to take the Ospreys 10 clear.

Having been dominant in the scrum, the Ospreys were surprised to penalised the next time the two sets of forwards packed down, and Paddy Jackson made no mistake with his first attempt, bringing Ulster back to within a converted try.

In a game regularly punctuated by stoppages the next break came after Andrew Trimble completely misread the high ball, taking out Dirksen on the wing, but Morgan was well off target with his penalty attempt from the touchline.

The Ospreys coaches were forced into an unexpected reshuffle on 65 minutes when after using their second and back row replacements, James King was forced off with a hand injury, meaning hooker Scott Baldwin was forced into emergency duty on the blindside.

Another scrum penalty went Ulster's way, much to the annoyance of Ospreys players, coaches and supporters who felt that the opposition eight were simply running the scrum around. Nevertheless, Ulster took the opportunity to reduce the deficit further, Jackson's penalty making it 13-9 with a little under a quarter of an hour remaining.

A Dan Biggar up and under then put the Ospreys on the front foot, a good spell of possession creating an opening for young Tom Grabham on the left who showed a great turn of pace to scythe through the defence, only for some excellent scramble defence to close the door as the home crowd roared their team forward.

However, with time almost up and Ulster having failed to seriously stretch their opponents for some time, a thunderous run through midfield by Neil McComb punched a hole in the Ospreys defence, quick hands keeping the ball alive. John Afoa was held up on the line but quick reactions from Paul Marshall saw him dive over to ground it, TMO Tony Rowlands confirming the score to put Ulster in front for the first time on the night with just five minutes to go, Jackson's conversion making it 16-13 to the visitors.

The bonus point almost slipped out of the Ospreys grasp in the final minute as Ulster camped on their line but a penalty for holding on meant there was to be no further scoring on what was, ultimately, a disappointing night for the reigning champions.