Sonny Parker scored a brace of tries - one in either half but Holley hailed his forwards' as the Ospreys complete their Italian job in style.
Holley said: "I thought our forwards were outstanding. They needed to front up today but Richard Hibbard was outstanding with his ball-carrying and his work-rate.
"Ian Gough and Alun Wyn showed the intensity and durability that has given them Wales honours, and Jonathan Thomas is coming back to great form.
"Jonathan is a versatile player and one of our leaders. He played well too so it's good news for the Ospreys and Wales."
The Ospreys flew into a commanding 19-point lead through tries by Parker, Alun Wyn Jones and Jonathan Thomas before Filo Tiatia claimed the bonus point in the 58th minute.
The nature of the victory was made all the more sweeter for the visitors who were without skipper Ryan Jones through a foot injury and Gavin Henson who did not travel to attend the imminent birth of his second child.
And the second successive maximum for the Ospreys against the Italians put the pressure on their rivals.
Holley said: "We have got the result and performance we wanted so we will just have to wait and see now. All we want is to have our own destiny in our own hands.
"The idea was to put the pressure on the other two, but either one of them tomorrow can put the pressure back on us.
"Treviso are not a bad side and made things difficult for us but the players did exceptionally well to keep their discipline and impose their own game.
"We always knew it was going to be a very difficult place to come.
"I'm delighted with the players and it shows we are making strides. We are maturing and to come away with five tries in these conditions is really pleasing."