The Sky Blues champions made it consecutive league wins as a five-star display in the first-half helped them seal a comfortable win in the south coast.
After making a fast start against Graham Potter's side, Ilkay Gundogan opened proceedings for the visitors after Bernardo Silva found the German to tap home into an empty net following a mistake from Robert Sanchez.
Foden, who was at his sumptuous best against the Seagulls, made it two following a quick break, as the 21-year-old was set up by Jack Grealish after a clever through-ball by the in-form Bernardo Silva.
The Stockport-born midfielder soon made it three after Gabriel Jesus's strike deflected off him and beat Sanchez, as City went into the break with a three-goal cushion.
However, Pep Guardiola's side slightly took their foot off the gas following the break, as they allowed Brighton to try and force their way back into the tie.
"We're disappointed with the second half, the level wasn't the same, but we dug in there," said Foden in his post-match interview with Sky Sports.
"Sometimes when you're 3-0 up, you can drop the level. From the start, we looked very good in possession, we controlled the game."
The England international has been in a rich vein form since recovering from a foot injury that kept him out of action for the first few weeks for the 2021/22 campaign.
Foden rounded off a sensational individual display by teeing up Riyad Mahrez in the closing stages, who made it four for the Manchester side by netting his seventh goal across all competitions this season.
You can follow us for live updates here: @City_Xtra