Treviso (10) 16
Try: Williams Cons: Marcato Pens: Marcato 3.
Ospreys (19) 36
Tries: Parker 2, Wyn Jones, J Thomas, Tiatia Cons: Hook 3, Biggar Pen: Hook.
Alun Wyn Jones heads for the line as the Ospreys win in Treviso
The Ospreys continued their challenge for a place in the Heineken Cup quarter-finals with a bonus-point Pool Three win at Treviso.
The Welsh region's performance did not reach the heights of the previous weekend's 68-8 win over Treviso.
But tries from Sonny Parker (2), Alun Wyn Jones, Jonathan Thomas and Filo Tiatia ensured the visitors' victory.
Treviso replied through a Brendan Williams breakaway try and three penalties from fly-half Andrea Marcato.
The Ospreys continued where they left off the previous weekend at the Liberty Stadium, with Parker, Wyn Jones and Thomas crossing in the first 25 minutes in which the hosts were down to 14 men for 10 minutes after Hottie Louw was sin-binned for illegally taking out James Hook.
Parker was the beneficiary of his own good work at a breakdown in which he stole possession, the Wales centre finishing off a move continued by Ian Gough and Andrew Bishop to cross for the opening try.
Three minutes later lock Wyn Jones powered over from close range and in the 25th minute front-row union members Adam Jones and Richard Hibbard paved the way for Thomas to break free.
Fly-half James Hook converted Wyn Jones' and Thomas' tries, while Treviso belatedly got on the scoreboard through a 30th-minute penalty from Hook's opposite number Andrea Marcato.
Home fans had something else to cheer when Parker's inside pass, intended for Tommy Bowe, was intercepted by Williams.
The Australian full-back raced 70 metres untouched to score Treviso's first try, ending a run of 13 the Ospreys had scored to that point in their back-to-back encounters.
Marcato converted the 34th-minute try and brought his side back to within six points of the visitors with a penalty four minutes after the break when the Ospreys were penalised at a scrum.
Three minutes later Hook replied, only for Marcato to again bring his side within striking distance with his third penalty.
The hosts' rush-defence often frustrated the Ospreys, particularly the effort the Italian side put into marshalling the threat of Wales wing Shane Williams.
Video ref Geoff Warren called a knock-on after Adam Jones was dragged down short and scrum-half Rhodri Wells attempted to ground the ball.
But the Ospreys won a penalty at the resulting scrum, skipper Paul James opting to pack down again.
At the third attempt Tiatia touched down as the home pack was marched back across their own line for the Ospreys' bonus-point try, Hook converting.
Parker crossed for a second time in the 78th minute and Hook's replacement, Dan Biggar, converted to round off the win.
Treviso: Williams, Vilk, De Jager, Waters, Goosen, Marcato, Botes, Sbaraglini, Intoppa, Di Santo, A. Pavanello, van Zyl, Gilbride, Louw, Kingi. Replacements: Horak for Marcato (62), VIdal for Intoppa (51), E. Ceccato for Di Santo (50), E. Pavanello for A. Pavanello (51).
Not Used: M. Barbieri, Filippucci, Lucchese.
Sin Bin: Louw (6).
Ospreys: Byrne, Bowe, Parker, A. Bishop, Williams, Hook, Wells, James, Hibbard, A. Jones, Gough, A. Jones, Thomas, Holah, Tiatia. Replacements: Biggar for Hook (76), Webb for Wells (79), Shervington for Hibbard (71), Tandy for Holah (74), Smith for Tiatia (71).
Not Used: Griffiths, Vaughton.
Ref: R Debney (RFU).