Kevin De Bruyne's 14th-minute opener was a collector's item as he celebrated scoring his first-ever Premier League header, diving towards a curling Kyle Walker cross to loop his superb effort from around 15 yards out over Jason Steele and into the top corner.
The Belgian then watched in-form attacker Phil Foden score twice in the space of eight minutes to put the Citizens in cruise control, firstly firing in a deflected free kick before coolly stroking home his second after a mix-up in the Brighton defence.
Julian Alvarez added a fourth just after the hour mark, and ended his 10-game Premier League goal drought in the process, with a close-range finish after some dogged work down the right from Walker.
Brighton had no answers to Man City's dominance, although they were controversially denied a penalty when Josko Gvardiol clipped Joao Pedro 20 minutes from time.
Substitute Jeremy Doku came close to adding a fifth when he burst through one-on-one in the closing stages, but Pep Guardiola's side got the job done and claimed a statement victory to edge themselves closer to an unprecedented fourth successive Premier League title.
Ruthless Man City put pressure on title rivals Arsenal
Man City have become only the fourth Premier League team to score four or more goals in four consecutive Premier League matches; they have netted 17 goals in total across four fixtures in April, five more than they managed in February and March combined.
Not only has City's four-goal victory over Brighton helped their goal difference, it has also extended their club-record unbeaten run to 30 games in all competitions, a run that includes 18 without defeat in the Premier League.
Victory for Guardiola and co has seen them leapfrog Liverpool - who suffered a 2-0 defeat at Everton on Wednesday - into second place in the top-flight standings, and just one point now separates the Citizens from leaders Arsenal, who have played a game more than the reigning champions.
As for Brighton, their winless run has been extended to five matches and Roberto De Zerbi's men remain 11th in the table, six points behind the top seven with only five matches left to play.
Phil Foden - Stockport lad sprinkled with stardust
Not for the first time this season, Foden ran the show for Man City, and having increased his goal tally in all competitions to 24, 16 of those netted in the Premier League, it comes as no surprise to hear the England international's name in the conversation for Player of the Season.
Foden loves playing at the Amex and he has now scored six goals across his last four visits to Brighton's home stadium, while he has netted eight in 10 appearances both home and away versus the Seagulls.
The 23-year-old instigated City's opener as he bided his time in possession before playing a precise pass down the right to Walker, who swung his first-time cross into the box for De Bruyne to net a magnificent diving header.
Foden then jinked his way through a few bewildered Brighton bodies and was somewhat fortunate to win a free kick on the edge of the area. Although his 20-yard effort took a wicked deflection off the back of Pascal Gross, that did not stop City's No.47 from celebrating his 50th Premier League goal just before the half-hour mark.
The Stockport-born attacker is only the third player after Lionel Messi and Erling Haaland - the latter absent from the City squad through injury - to score 50 top-flight goals under Guardiola while aged 23 or younger.
Foden then capitalised on Brighton's attempt to play out from the back and intercepted Valentin Barco's tame pass on the edge of the area before placing a first-time shot beyond Steele into the bottom corner.
England manager Gareth Southgate was in attendance to cast a watchful eye over Thursday's action, and he is sure to be thinking how he can get the best out of Foden in his starting lineup ahead of Euro 2024.
Out-of-sorts Brighton made to rue defensive errors
Roberto De Zerbi has received plenty of plaudits for his attractive style of play during his 19-month spell as Brighton boss, but they have rarely reaped the benefits when adopting that risk-and-reward philosophy in recent months.
Brighton's bravery in possession can be admired, but mistakes in and around their penalty box have been punished too often and that was highlighted further in their defeat to Man City, who looked sharp all night with their high press.
The Seagulls have made more errors leading to goals (nine) than any other team in the Premier League this season, including one that led to Foden netting his second to put the game to bed with less than 35 minutes on the clock.
Amidst uncertainty over the long-term future of De Zerbi, Brighton have won only six of their last 27 Premier League matches, and after securing their highest ever top-flight finish (sixth) last season, they are in danger of ending the current campaign in the bottom half of the table.
Brighton will attempt to return to winning ways and reignite their top-seven hopes when they travel to the Vitality Stadium to face Bournemouth on Saturday, while Man City are next in action away against Nottingham Forest.