The defending league champions ran out comfortable winners over the Italian outfit, but had to wait until the 65th minute to register their try-scoring bonus point.

Winger Richard Fussell set the ball rolling with a seventh minute opener, and a penalty try and a late effort from full-back Lee Byrne sent the hosts in the break, armed with a 24-6 advantage.

Fly-half Riccardo Bocchino, who was making his first league start, kicked two penalties for Aironi who had Italian internationals Josh Sole and Marco Bortolami sin-binned in either half.

A second penalty try ensured the bonus point for the Welshmen, with Ireland star Tommy Bowe closing out the scoring 11 minutes before the finish.

Speaking afterwards, Ospreys forwards coach Jonathan Humphreys said: "Winning with a bonus point when only playing well in patches is a positive thing. We were pretty fractured in a lot of things tonight, and I can see why people get frustrated with us because I do as well, along with everybody else.

"But that's the way we are, we understand the circumstances, I've seen us do this before and hopefully we'll see it come together over the next couple of weeks.

"All the stats show that we were by far the most dominant team, we just didn't score as many tries as we should have.

"It's a bonus point win so we've got to be happy with that, although we know there are large things we have to work on."

Aironi, who suffered a heavy defeat at the Scarlets last weekend, made wholesale changes to their starting line-up.

The most notable inclusions saw back rowers Sole and Andrea Benatti, former Italy captain Bortolami, half-backs Bocchino and Michael Wilson and front rowers Luca Redolfini and Luigi Ferraro making their full Magners League debuts.

The Ospreys management made five changes to the team that lost to Munster in Limerick. Fussell took over from Nikki Walker on the right wing, and front row duo Adam Jones and Richard Hibbard, lock Ian Gough and flanker Ben Lewis were restored to the pack.

Lewis' evening was cut short by a neck injury in the first half, but his replacement, the 21-year-old Justin Tipuric, took his opportunity to impress in his first league game.

The deadlock was broken when Fussell crossed in the right corner on the end of a free-flowing move, which was sparked by Alun Wyn Jones' winning of a lineout ball and Bowe's run and final pass.

Fly-half Dan Biggar did well to add the conversion from the touchline, and the Ospreys continued to press, enjoying a plentiful supply of possession and territorial dominance.

Biggar and Bocchino swapped penalties before openside Sole was sin-binned for tackling Jerry Collins without the ball. Fussell, hunting for his fourth try of the campaign, was held up just short, before Lewis injured himself as the Ospreys tried to recycle possession. There was a lengthy stoppage as he was put in a neck brace and stretchered off.

A succession of five-metre scrums saw the 14-man Aironi eventually give way with the concession of a 30th minute penalty try, which Biggar converted for a 17-3 lead.

Bocchino kicked a fine penalty in response, and Aironi launched a counter attack that could have resulted in a try for winger Giulio Toniolatti. Bocchino and centre Gilberto Pavan took play up towards the halfway line, a kick from Pavan was missed by Shane Williams and the advancing Tonionlatti was unfortunate to knock the ball on as the Italians flooded forward.

But the Ospreys put 18 points between the sides when Byrne popped up on Williams' shoulder to take a pass and gallop through for a timely seven-pointer.

The Ospreys endured a frustrating time of it in the third quarter as they failed to turn pressure into points, with Aironi's committed defence contributing to a number of handling errors.

There were near misses for Fussell and replacement Ryan Jones as they looked to score from close range. Aironi's hopes were dented by the yellow card earned by Toniolatti for a deliberate knock on.

Bortolami's subsequent sin-binning for coming in at the side of a ruck was another setback for the Viadana-based side.

It was a key moment as during the next 10 minutes, the Welsh region scored two converted tries. Their scrum, with man-of-the-match Adam Jones performing well, earned them a second penalty try, after they had forced Aironi to deliberately pull down the set piece.

Replacement scrum half Mike Phillips was eager to get involved as the Ospreys hunted for a fifth try. He was at the heart of a couple of moves before number 8 Jonathan Thomas raided forward from halfway and Bowe, coming in on a lovely angle, took it up to glide through for his second try in as many games.

The successful conversion from replacement fly-half Gareth Owen was the last scoring act, as the Ospreys stretched their unbeaten home run in the league to ten matches.