However they slipped to a 57-14 defeat at home to the English champions, fading in the second half after a hard-fought opening 40 minutes.
And Venditti, who made his international debut for the Azzurri earlier this year, insists that his side's discipline will also have to improve ahead of the return fixture at the Stoop this weekend.
He said: "I think their physicality put us under pressure from the start, after that the gap grew and grew. We needed improved cohesion but the lead went up too quickly.
"The weather conditions were difficult for both squads. It was an intense game, and I think it was good to watch. We gave everything but Quins were superior. In the first time we spent so much time defending but eventually their quality came through and especially when we were down to 14 men they took advantage.
"The referee was good, it was our indiscipline which was costly compared to them, that is the biggest difference apart from the physicality."