Jeremy Doku, Phil Foden and Savinho - with a long-range stunner - were also on target as City produced an outstanding display despite both sweltering heat and a torrential downpour in Orlando on Thursday.
City were pegged back after Doku's early opener when Ederson gifted a goal to Teun Koopmeiners but their lead was restored when Pierre Kalulu turned into his own net at the Camping World Stadium.
Haaland, reaching a notable landmark in senior football for club and country, came off the bench to bundle in the third and Foden and Savinho made victory certain before Dusan Vlahovic's consolation.
The result means City progress with a 100 per cent record from their three group games and should, in theory at least, have a more straightforward route through the knockout stages.
Juve beat City 2-0 when the sides met in the Champions League in December but this was a far different side than the one that won just once in 13 games in a dismal run late last year.
It was also a notable shift in gear from City after opening the competition with two straightforward wins against Wydad Casablanca and Al Ain.
With Ballon d'Or winner Rodri making his first start since September, City were fluid and energetic.
They made a fast start and Bernardo Silva had a header saved by the feet of Michele Di Gregorio before they took the lead in the ninth minute through Doku.
Summer signing Rayan Ait-Nouri slipped him in with a fine throughball and the Belgian tucked home after cutting inside Kalulu.
Juve responded immediately and City failed to make the most of a reprieve after Vlahovic scuffed an effort wide.
Ederson carelessly gave the ball away from the resulting goalkick and Koopmeiners rifled a shot past the Brazilian.
City dealt well with the setback and Tijjani Reijnders, Rodri and Omar Marmoush all had attempts blocked.
The pressure paid off in the 26th minute although they benefited from a huge stroke of luck as Kalulu diverted Matheus Nunes's ball past Di Gregorio.
The ferocious sunshine gave way to heavy rain just before the break but City were not deterred as Savinho shot at Di Gregorio before the keeper pushed away further strikes from Ait-Nouri and Marmoush.
Marmoush was replaced by Haaland at the interval and the Norwegian soon made an impact.
Reijnders played in Nunes, who rolled a pass perfectly into the path of Haaland in front of goal. His connection was hardly the cleanest but such was his positioning he could hardly miss.
Ederson denied Vlahovic as Juve sought a way back but Haaland created the opening for the fourth when his pass was picked up by Savinho and powered in by Foden from close range.
Savinho added another in style when he thundered in a shot off the underside of the bar from distance after 75 minutes.
Juve were well beaten but Vlahovic battled on and pulled one back six minutes from time after good work by Kenan Yildiz.
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