The penalty was awarded for Neal Maupay’s handball from a corner kick as United rushed to find a last-breath winner, after Solly March tied the knot in the fourth minute of added time.
Fernandes said he had to have “balls” to find the net and earn the Red Devils first championship points of the season.
But he also credited the role Fred played, revealing he was able to stay focused because the Brazilian midfielder continued to protest Brighton players away from him.
“As everyone starts screaming, chatting, VAR and everything, I’m trying to stay out of the way, take the ball and stay on course,” Fernandes said in quotes reported by the Manchester Evening News.
“I saw the keeper take his bottles and everyone, the towel came out, so I was just taking the ball, waiting, ‘focus on what you have to do.’
“Of course we sometimes say you have to have balls to take a penalty like this.
“I know everyone trusts me, everyone expects me to score, and that was a big part of the game like I said.
“Penalties are the key in some games and that was the key today. It doesn’t matter if I score, or if someone else scores – what matters is the three points we get.
“After receiving the penalty, everyone fought for everything:” penalty, no penalty “. We stayed the course until the end. I felt the confidence of everyone behind me.
“I see Fred fighting with everyone who came to distract me from my focus, pushing the players away from Brighton. “
Manchester United are looking to forge their way to the top. Ole Gunnar Solskjaer has already brought in Donny van de Beek but Jadon Sancho remains Manchester United’s number one target.
And you can follow their journey by signing up for the brilliant new Mirror Football newsletter!
From the latest transfer news to calendar setting stories, get it all delivered to your inbox.
Signing up is easy. Put your email at the top of this article or follow the instructions on this link.
Brighton had taken the lead thanks to a Maupay penalty five minutes before half-time, but United equalized two minutes later thanks to a goal against their own Lewis Dunk.
Solskjaer’s side were dominated for much of the game by their hosts, who hit the woodwork five times.
But Marcus Rashford’s superb solo effort gave United a lead in the second half, while March appeared to have secured what would have been a deserved draw for Brighton, ahead of late winner Fernandes.