Ruben Amorim said he was proud of his players for believing something "magic" could happen in "Fergie time" after earning his biggest win yet as Manchester United manager with a 2-1 win against rivals Manchester City.

United were trailing 1-0 before Bruno Fernandes struck an 88th-minute penalty and Amad Diallo -- hailed as "unstoppable" by his captain -- netted a late winner, befitting of Sir Alex Ferguson's team of old.

"Fergie time" was famously coined about Ferguson's United teams frequently scoring in the allotted stoppage time, and often beyond.

"It was incredible," Amorim told the BBC about the finale at the Etihad Stadium. "I think we deserved it. It was a very tough match but we believe until the end. We managed to score, we needed that win, it was important for us and for our fans.

"We were in the game for 90 minutes and that is very good. We talk about the Arsenal game, we played well in the first half but they were not believing that we could win. Today was so much more different.

"I also believe. Then we have Fergie time and we put the things together and something magic happened. It was a good day for us."

The win at a beleaguered City outfit was a statement victory for Amorim, who arrived from Sporting Club in November, and a much-needed one after back-to-back Premier League defeats. Heading into Sunday, United had lost 2-0 at Arsenal and 3-2 against Nottingham Forest.

"They [the fans] needed it," Amorim said. "Just like us, but you can see the way they celebrate is special. But we need to continue. Our club needs to win these kinds of matches, I understand the happiness of our fans but we need to continue.

"We need to improve a lot of things but today the guys deserved the win. They were in it until the last minute and that is important for us."

United's saviour on Sunday was Amad who is revelling in a prominent role in Amorim's system, particularly with Marcus Rashford and Alejandro Garnacho dropped from the squad entirely at the Etihad.

The youngster earned the penalty for the opener and skillfully rounded Éderson for the winner.

Fernandes told Sky Sports about Amad: "He showed again today he is always alive. That is why he gets the penalty, why he gets the goal. He has been brilliant. When he is like this he is unstoppable.

"I just want him to keep working, that is what he has been doing. It is great what he did today but I am sure he can do this every week. We want this week in, week out. He is now getting his chances, deservedly."

Amorim stressed the need for patience with the winger but still praised his progress.

"Erik [Ten Hag] and Ruud [Van Nistelrooy] did a great job with him, we continue that," Amorim said. "Really important. All the players fit in my system. If they want to be in it, if they are talented, every player can fit in this system.

"He can play different positions, he is very humble. We have to be very careful with Amad because sometimes in our club we put young players in a special place. Lets stay calm with him."