They travel to Italy for the second leg match on Saturday with coach Ricardo Sequeira calling for a repeat display from his team.
"Our win over Leonessa on Saturday was very important for Portuguese rugby," said Sequeira. "It was the first ever win by a Portuguese side over an Italian side and we are going to Italy this weekend to win.
"The team is confident and it would be a fantastic achievement to win both matches. Even though we only have a narrow 12-point advantage, the players are prepared to work very hard in Italy.
"The team spirit was excellent last weekend and I am going to need all 22 players to be as committed again this time around. I don't want to mention any players in particular but it is the whole team that counts at this stage.
"I think we surprised the Italians on Saturday - but we won't have that advantage twice and it will be a lot more difficult.
"All of us - the players and the coaching staff - are thrilled to be playing in the Parker Pen Shield.
"We haven't had much time to prepare for these games because there was no break in our national competition. Hopefully, next year, the Portuguese Championship will stop so that we can prepare better for this competition."