The Portugal international has voiced his satisfaction with his side's win at White Hart Lane in the first leg of the last-16 clash, but says anything can happen in the return leg
The Lisbon giants went two goals up via Rodrigo and Luisao before Christian Eriksen pegged one back, but again Luisao made sure Benfica returned to Portugal with a two-goal lead.
"It is still a dangerous result for us," Amorim told SIC after the final whistle.
"Tottenham have some great players who have the quality to do in the return what we did here at White Hart Lane.
"One of our biggest strengths is our quick transition from defence to attack and we managed to score three goals here.
"It is very important in knockout games to score in away matches."
Spurs boss Tim Sherwood accused Benfica boss Jorge Jesus of having a lack of class for his actions during the match, stating: "I thought [Jesus'] team were very good and showed a lot of class. It's a shame he wasn't the same.
"He doesn't mind himself, does he? Waving goodbye like that lacks class. Why would anyone do that? Not for me, thank you."
The Portuguese side's coach, meanwhile, defended his approach, stating: ""Maybe here in England the benches are too close compared to in Portugal. In Portugal, we have more space and can express ourselves in our own way."
The return takes place at the Estadio da Luz next Thursday.