The Italians provided more stubborn resistance in the second half with three tries of their own in a thrilling end-to-end encounter.
However, Warriors were not to be denied and a brace of penalty tries plus scores from Graham Kitchener and a first Worcester score from Hal Luscombe secured the dream result.
"We were clinical in the first half. We sent the boys out to score eight tries and they did that in style," said Ruddock.
"We wouldn't normally say those kind of things to the players, we didn't want to be disrespectful to the opposition. But the reality was a big prize was on offer with a home quarter-final.
"We had to push the boundaries back, we had to go out and play and that is what the lads did.
"If you look at Petrarca they played some good rugby at times and when we gave them the ball they scored some good tries at times. They have some good players and some experience.
"They weren't mugs and if we hadn't had played so well they could have caused us some problems.
"You have to say our performance was really good, at times it was excellent. There were still things we would like to get out of our game but our intent was fantastic.
"It showed how well we played when they came back in the second half, they didn't fold or give in."
Ruddock was also delighted with the manner in which his side had blown away the rust of last weekend against Bucuresti and set themselves up for the rearranged clash with Sale Sharks.
"We have to look at the Bucuresti game in context. We still scored six tries and we hadn't played for three weeks," he said.
"There were handling errors on that day, it was colder and wetter, but today we were fluent and we had flow to our play with our passing and width.
"It was everything I was looking for from a coaching point of view. The only negative was letting in a few tries towards the end. That will be the big area we will focus on in the debrief ahead of the Sale game."