Arsenal's 1-0 win over Crystal Palace — secured via a brilliant scissor kick by former Palace player Eberechi Eze — was made all the sweeter by City losing 1-0 at Aston Villa on Sunday, with right back Matty Cash grabbing the winner from a fierce 19th-minute strike.
It was City's first defeat since August 31 and meant Haaland's scoring run for club and country — stretching back even further, to August 23 — is finally over.
The Norway striker did bundle the ball into the net in the 90th minute, before crashing into the post, but the goal was ruled out for offside.
With beleaguered Liverpool losing 3-2 at Brentford on Saturday, it has been a bad weekend for Arsenal's chief title rivals.
Somewhat surprisingly, Arsenal's closest challengers now are Bournemouth, who won 2-0 at home to Nottingham Forest.
Even more unlikely is the sight of promoted Sunderland a point back alongside third-placed Tottenham, who won 3-0 at Everton. City are one point further adrift in fifth — and already six points behind Arsenal.
"It's very early, we're still in October," said Arsenal manager Mikel Arteta, whose team is seeking a first Premier League title since 2004. "The emotional state is really high but there are a lot of things to get better."
Not that City manager Pep Guardiola is too concerned yet.
"I was worried before the international break in September when we were 14th in the table," Guardiola said.
"If they win all their games and win the Premier League, congratulate them. That's all we can do ... but I don't live in October and November thinking, 'Oh, what is going to happen if we don't win the Premier League?'"
Eze, with his first league goal for the Gunners, barely celebrated after producing a wonderful finish from Gabriel Magalhaes' nod-down to ultimately clinch a fourth straight league win for Arsenal.
"The technique is unbelievable," Arteta said of the England playmaker, who started the season with Palace before completing a Stg £60 million ($A123 million) move to Arsenal, the team he supported as a kid.
Haaland was unable to make it seven straight Premier League games on the scoresheet as Villa defended stoutly in the face of a late City onslaught to record a third straight home win over Guardiola's team.
During the summer, Bournemouth lost three of their back-four and also their goalkeeper from last season.
It hasn't stopped the team making an unexpectedly good start — and a prolific new striker has been unearthed too in 19-year-old striker Eli Junior Kroupi, a France under-21 striker who scored his fourth goal in three appearances.
But Forest suffered again in Sean Dyche's first league match in charge following Ange Postecoglou's sacking.
Centre-back Micky van de Ven scored two first-half goals at corners and Pape Sarr added a late third for Tottenham in their win at Everton.
Burnley scored in the fifth minute of stoppage time to win 3-2 at last-placed Wolverhampton, who've yet to win any of their first nine games of the campaign for the second straight season.
Wolves manager Vitor Pereira was involved in a heated exchange with his own unhappy fans after the game.
