Similar to United's Champions League final victory over Bayern Munich in 1999, United staged an amazing late fight-back to score three goals in extra-time to win the second-leg 5-4 and reach the semifinals 7-6 on aggregate.
Amorim revealed afterwards, "I was watching again the '99, the documentary (when United completed the Treble by beating Bayern Munich with two late goals in the Nou Camp), so to have some inspiration for this moment. But, it was a great night.
"I think the team were tired and you feel it during the game, and then 4-2 with one more player and, in the end, you think it's over. But here, it’s never over."
On matchwinner Harry Maguire, he continued: “We tried to put Harry Maguire (up there) because he's the only guy that can score a goal with his headers.
"And then Kobbie Mainoo, he has a lack of pace in this moment because he had that injury and he stopped for a while, but he's really good on short spaces, and then he has the ability to do that kind of goal. And then we try it, and sometimes it works, and today was a good day.”
Shaw stood up on the night
Amorim also heaped praise on Luke Shaw for his commitment on the night.
He explained, "When you are here, you can feel that playing Premier League and European games is really hard. If you don't have the full squad, it is almost impossible. Mason Mount brings us experience.
"You can see Luke Shaw. Luke Shaw was meant to play 30 minutes, top, but then we had a problem with news at half-time, Vic had a personal problem, he had to leave. Nous too. So, all this stuff happening during this game, but, in the end, it was a good day.”
On the atmosphere generated by the fans, Amorim admits he's never experienced anything like it in his career.
“I think, if you see the goal of Kobbie and Harry Maguire, the sound of the stadium was the best sound ever. You want to keep that. Sometimes people want to keep a lot of things, shirts and, I just want to keep that sound. It’s the best sound in the world. It’s a special moment. It was amazing.
"When you score two goals in the end, like that, you hear the sound of the fans and it pays off any suffering or frustration you have during the season. And, we know again, we know that we are underperforming. We deserve all the critics, but we still have time to make something special of this season, so we have to think like that and to be positive.”