The onslaught started almost immediately and the visitors had to make three blocks inside their six-yard box in the first five minutes, but even so it wasn’t long before the breakthrough came - Foden curling home inside the near post after Bernardo Silva’s low cross.
It was relentless from the hosts and Erling Haaland scored twice and four minutes before teeing up Foden for a second too, all before the half-time whistle.
Antony curled in an unexpected consolation but that just reawoke City’s hunger, with Haaland hitting his hat-trick and then teeing up Foden for his two, before United scored two very late goals through Anthony Martial.
Here are the player ratings from the Etihad Stadium.
Ederson, 6 - Had one of the best seats in the house for a very relaxing afternoon. Made life tricky for himself once in the first half but other than that, untroubled. After the break it was a different matter and he should have done better with saving from Fred before Martial headed in the rebound.
Kyle Walker, 6 - A couple of recovery runs were necessary but he was replaced in the first half through injury.
Manuel Akanji, 6 - Despite City being far and away the better team there were a few shaky moments from Akanji with decision-making on the ball. Strong when running in possession, though.
Nathan Ake, 7 - Composed throughout and did well one-on-one for the few occasions he was called upon. Probably will be annoyed a couple of teammates fell asleep to concede one or two of the goals.
Joao Cancelo, 6 - Unusually low-key in build-up play as he remained deeper on this occasion. Gave away a late penalty.
Ilkay Gundogan, 8 - Excellent in the first half for both winning back possession quickly, sparking attacks with fine passes between the lines and even getting himself into the box for chances on goal.
Bernardo Silva, 9 - Relentless with tenacity, scintillating with his passing. Set up the opening goal with a fizzed cross and was a joy to watch.
Kevin De Bruyne, 9 - Possibly even better than Silva, with a magical assist for Haaland’s second and far too much intelligent movement for United to keep track of.
Phil Foden, 9 - A hat-trick for the local boy after two smashing finishes inside De Gea’s near post and another which was briliantly tucked away.
Erling Haaland, 10 - A third straight home Premier League hat-trick is ludicrous enough but it’s also his third hat-trick in just eight Premier League games. Also racked up two assists on the day. An amazing and frankly ridiculous striker.
Jack Grealish, 8 - Started the game in excellent shape, winding past United defenders at will and helping open the game up spectacularly. Should have scored and faded after half-time.
Subs: Gomez 7, Mahrez 6, Alvarez 6, Laporte 6.
David de Gea, 4 - Nothing he could do about some of the goals, and even made a couple of early saves to stop his side falling behind initially, but was beaten twice at his near post, didn’t dominate his six-yard box let alone his area and was spent most of the game picking the ball out of his net.
Diogo Dalot, 2 - Destroyed right from kick-off by Grealish, booked in under 100 seconds and beaten repeatedly in the lead-up to first-half goals. An absolute nightmare.
Raphael Varane, 5 - Perhaps the best United defender simply by virtue of going off injured after only three.
Lisandro Martinez, 3 - Just utterly incapable of stopping Haaland, which in fairness is far from unique to the United man.
Tyrell Malacia, 3 - Not much better than his teammate on the right. Out of place and beaten for pace for Foden’s second. Subbed at the break after a torrid 45’.
Scott McTominay, 4 - His passing was dreadful in the first half and constantly put his team under pressure, but in fairness he fought back, tried to get closer to City’s midfielders and had a few better moments thereafter.
Christian Eriksen, 3 - Looked lost whether it was trying to stop City’s central players on the ball or, for some bizarre reason, marking Haaland off set-pieces.
Antony, 4 - Largely anonymous in the first half and offered no help defensively. Curled in a beauty after the restart but only served to help spark City back into life.
Bruno Fernandes, 3 - One of the worst on the pitch with a petulant showing which offered no quality on the ball, no goal threat and nowhere near enough defensive help.
Jadon Sancho, 4 - Initially a bit of an out-ball but his small influence quickly faded. Subbed second half.
Marcus Rashford, 4 - Made a few runs in behind early on and looked like he might trouble Akanji once or twice but was given no service.
Subs: Lindelof 5, Shaw 5, Martial 6, Casemiro 4, Fred 5.