The Brazil striker admitted some relief to have made the breakthrough.
"Yeah, finally!" said Cunha afterwards. "Wow. I worked so hard for this. The win (for) start(ers), to come in and I'm so happy.
"But of course I want a little bit more contribution and then today's coming, (but) we win and then everything's fine.
"We have little actions (but) when you play in the front, (you have) to score goals. I have (to have) more contributions. But the last time I said this, if my participation is to help the team and then we start doing (well), I'll be happy also.
"But of course with this goal, everyone will be around me to push me. The guys started to joke and then said: 'Wow, you can score!'. These things happen and everyone pushes me and I feel so happy to be here."
On manager Ruben Amorim, Cunha also said: "Everyone has full confidence in (Ruben) Amorim. He is someone that pushes us forward.
"He is always very stressed until we start to win, and then he improves every day. Of course, he deserves this, Man United deserve this.
"This needs to be the normal for this club. I am so happy to be a part of this. Amazing day, I will remember this.”