Playing into a strong wind before the break and a man light the Ospreys trailed by nine points at the turnaround, but despite dominating the final 40 minutes they had to settle for a losing bonus point as they launched the defence of their PRO12 crown.

A day of unseasonal Italian rain had left the surface very wet but the clouds had parted to leave clear skies by the time Dan Biggar got the game underway just past 8.05pm in Treviso.

A penalty for coming in from the side provided Treviso with an early opportunity to take the lead and despite his unconvincing kick that just about cleared the crossbar, Kristopher Burton was able to grab the first points of the night, the Italians going 3-0 up in the sixth minute.

The Ospreys were reduced to 14 just a couple of minutes later, Ian Evans sent to the sinbin for killing the ball on the floor after finding himself isolated.

Burton then doubled his side's lead with a straightforward kick from in front of the posts after an offside decision against the Ospreys.

An indisciplined start from the Ospreys was proving costly, and it was 9-0 on 14 minutes, Burton making the most of another offside decision.

Having spent most of the opening quarter inside their own half, the Ospreys were able to get themselves on the scoreboard when a rare attacking foray resulted in a penalty, Biggar making no mistake.

Burton had a chance to restore the nine-point advantage minutes later after Tom Isaacs was guilty of hanging onto the ball, but despite having a strong wind to his back he was unable to find the target from the 10m line.

The Ospreys were struggling to keep hold of the ball, turning it over repeatedly, and having lost possession from an attacking lineout they found themselves retreating as Treviso worked their way up to the Ospreys 22.

The Italian team's progress was halted abruptly by a high tackle from Evans, back on the field just a matter of minutes, leaving the referee with little option but to issue a second yellow card to the big second row - followed immediately by a red one - leaving the Ospreys to play 50 minutes a man light. Burton made it worse when he slotted over the resulting penalty, his fourth of the night.

The response from the men in black was a positive one, putting together their best period of possession which ultimately led to a penalty against Edoardo Gori but kicking into the wind Biggar was just off target.

That left the Ospreys trailing by nine as they turned around, and although they wouldn't have been too disappointed with the scoreline having played into such a strong wind for the first 40, there's no doubt they would've been aware of the size of the challenge facing them playing a man short.

HALF-TIME: BENETTON TREVISO 12 OSPREYS 3

It was important that the Ospreys started the second half strongly and they had a chance to grab the first points just a couple of minutes in after some positive play took them upfield, Biggar hooking a penalty across the face of the posts and wide.

More good play from the Ospreys saw them keep up the early pressure, spreading the ball wide and looking to keep it alive, and as they moved close to the Treviso 22, tighthead Ignacio Fernandez-Rouyet was pinged for not rolling away. He was yellow carded, equalling out the numbers on the pitch for 10 minutes, while Biggar was able to slot over the kick from the left, bringing the Ospreys back to within six points.

A half-break from Biggar almost created an opening, the fly-half carrying 30m upfield. With Hanno Dirksen on his outside, he opted to look for Kahn Fotuali'i inside but a Treviso hand prevented the ball finding the target, allowing the Italians to clear.

The Ospreys were on top and the TMO was called into action 53 minutes in as Ashley Beck looked to finish off another counter attack, the decision eventually going in favour of the defence, Tommaso Iannone doing enough to hold the centre up on the line as he attempted to slide his way over.

Just minutes after being restored to 15, Treviso again found themselves on a par numerically with their visitors when replacement lock Dean Budd was yellow carded for a dangerous tackle on Richard Fussell as the Ospreys fullback looked to deal with a Luke McLean kick and chase.

An offside decision against Simone Favaro gave Biggar another chance for goal, but for the third time he was off target.

It was a messy, ugly game, but as it moved into the last 15 minutes the Ospreys were still well in contention and they almost carved an opening from a scrum in Treviso's 22, Fussell coming into the line before looking to feed Isaacs, but the wing was unable to gather with the line beckoning.

The second half had been all Ospreys but they had been unable to find a way through the stubborn Treviso defence. A penalty in the 79^th minute allowed replacement fly-half Matthew Morgan to put his team in the corner, but although the pack hammered the line they were unable to find their way through, Rhys Webb's knock on a metre out the final act on a disappointing evening.