But that owed more to City’s early season struggles than signs of progress for Amorim’s men, who have taken just four points from their opening four games and been dumped out of the League Cup by fourth-tier Grimsby.
“In these kind of games we need to be perfect and in this game we were not perfect,” said Amorim.
“The frustration is always the same because with the amount of chances (we create), we need to score goals.”
To cap a fine City display, goalkeeper Gianluigi Donnarumma marked his debut with a stunning save from Bryan Mbeumo to deny United a foothold in the game at 2-0.
City remain six points adrift of leaders Liverpool, but victory is a huge confidence boost for Pep Guardiola’s side ahead of facing Serie A champions Napoli and Premier League title rivals Arsenal next week.
“We needed this,” said Haaland. “You always want to win the derby but you could feel it extra today.
“I’m so relieved, so happy we managed to do it altogether. We have to keep going.”
Before kick-off, both sets of fans put rivalry aside to pay tribute to boxing legend Ricky Hatton, who died on Sunday at the age of 46.
A massive City fan, Hatton’s face was displayed on big screens during a minute’s applause.
Foden, a fellow boyhood City supporter, said before kick-off that the news gave the home side extra motivation to win in Hatton’s honour.
And the England international was central to a much-needed victory after a difficult start to the campaign for him personally and City as a whole.
Foden was the Premier League player of the season in the 2023/24 campaign, but his form dipped drastically last season.
Fitness issues meant he had not started a game this season until Sunday, but he took just 18 minutes to make his mark.
United’s defence allowed Jeremy Doku to bundle his way to the by-line and the Belgian’s cross picked out Foden, completely unmarked, to head in the opening goal.
Donnarumma decisive
Doku was the creator once more when City doubled their lead on 53 minutes.
Haaland showed his power, pace and incredible precision to dink the ball over the onrushing Altay Bayindir.
City’s number nine went from the sublime to the ridiculous moments later when he missed an open goal with the chance to double his tally.
United were architects of their own danger as Matthijs de Ligt’s poor pass set up a City counter-attack.
Tijjani Reijnders’s dummy set Haaland clear on goal, but after rounding Bayindir, he could only hit the post on the stretch.
Moments later, Donnarumma produced his moment of magic to prevent what could have been a turning point.
Mbeumo’s sweetly-struck volley was arrowing into the bottom corner until the Italian reached out a giant right hand to turn it behind.
What could have been 2-1 was soon 3-0 thanks to another United gift.
Harry Maguire this time gave away possession to Bernardo Silva, who set Haaland racing away into the vacant United half and he kept his cool to score for the eighth time in nine appearances against United.
City fans goaded Amorim with chants of “sacked in the morning” in the closing stages.
The Portuguese is not in danger of an immediate dismissal, but his Premier League record now reads a dismal eight wins in 31 games.
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