Ben Yedder came off the bench to score a double and lift Sevilla to a 2-1 win at Old Trafford in the second leg of the last-16 tie.
The result came after a 0-0 draw in the first leg and Ben Yedder was delighted for Spanish side, who reached the quarter-finals in Europe's top club competition for the first time in its current guise.
"I'm happy, very, very happy. It's a beautiful evening. It's a match that we won't forget in a long time. It's the happiest day of my life," the Frenchman told beIN SPORTS .
"I don't know how to describe my emotion. It's a child's dream to win against big players, big teams like Manchester United. There is a lot of emotion.
"We will try to savour it all together. We enter the history of the club, this is the first time we go to the quarter-finals of the Champions League. This is exceptional."
Ben Yedder was introduced in the 72nd minute and the forward quickly had an impact, scoring twice in six minutes after coming on.
The 27-year-old played down any suggestions he had an issue with Sevilla coach Vincenzo Montella.
"It's complicated, but it's part of life – play, be a substitute, wait for your time. Sometimes patience pays. That's what I always thought," Ben Yedder said.
"Everyone said there were problems between me and the coach, there is no problem. He made me go home, he trusted me, and I gave him back as I could.
"I always closed my mouth and worked. The coach was happy, I was happy. It's all that matters."
Montella was equally delighted with his side's performance, praising his players for giving their all at Old Trafford.
"I'm very, very happy, it's amazing we've won in this very special stadium," Montella told his post-match news conference.
"I have some very happy players who have got Sevilla in their soul and in their heart. All the players were fantastic, they played the game of their lives.
"Even though we didn't create chances in the first half we put in a good performance. I felt we were in control possession wise and we gave them very little opportunity to get close to our goal.
"In the second half I'm pleased Ben Yedder turned things around and it was he who made the difference. He was decisive and finished well on two occasions."