The Norwegian put Ipswich to the sword last weekend and followed up with another treble to take his tally to 70 goals in 69 Premier League games since joining City from Borussia Dortmund.
City have started the defence of their title in ominous fashion for those looking to depose Pep Guardiola's men after winning the league for four consecutive seasons.
The English champions are the only side so far to win all three of their opening fixtures before an upcoming international break, helped in no small part by Haaland's electric start.
"No words for him. All we can do is make him play better and better and give him as many balls as possible to the box," said Guardiola.
The City boss could again afford the luxury of leaving Rodri, John Stones and Kyle Walker on the bench after their exertions in reaching the final of Euro 2024, while Phil Foden missed out for the second successive game through illness.
In contrast to most of his team-mates who were in action at the Euros and Copa America, Haaland had the summer off from international duty and looks as refreshed as he has been ruthless.
"I feel good, I feel energised. I had a long vacation and pre-season," said Haaland.
"Only footballers know how important it is to have a break.
"You need to calm your body and mind down because it's a long season. It's not as easy as people think. I feel fresh and that's the most important thing."
After scoring in the opening weekend win at Chelsea and hitting his 10th City hat-trick against Ipswich, Haaland is now up to a Premier League record seven goals in the first three games of a season.
West Ham only had themselves to blame for the opener as they coughed up possession deep inside their own half and Bernardo Silva picked out Haaland to coolly slot beyond Alphonse Areola.
City looked set to put the game to bed in the opening stages as Areola denied Kevin De Bruyne before the Belgian smashed a shot off the crossbar.
But with West Ham's first purposeful attack they were level thanks to a helping hand from the visitors.
At the end of an impressive move from one end to the other, Jarrod Bowen drove into the City box and his low cross was turned into his own net by Ruben Dias.
City quickly restored their grip on proceedings and their lead with an intricate move of their own that ended with a resounding finish.
Rico Lewis' pass found Haaland, who then picked his spot and smashed the ball high past Areola.
Haaland should also have had an assist before the break as Lewis fired over from his deft lay-off.
City left the door open in the second half as they failed to find the killer third goal and could have been punished.
A lightning counter-attack saw Bowen play in Mohammed Kudus, who cannoned a powerful effort back off the post.
Haaland, though, fittingly had the final say to seal the three points.
The 24-year-old was played in by Matheus Nunes and confidently scooped the ball over substitute 'keeper Lukasz Fabianski.
And the veteran Polish stopper was called into action to deny Haaland a fourth in stoppage time.
A second defeat in three games for West Ham leaves Julen Lopetegui's men down in 14th.
