Erling Haaland took his goal total to 22 this season as Manchester City moved to within a point of Premier League leader Arsenal on Saturday.
Kevin De Bruyne added a third after Leandro Trossard had briefly put the result in doubt.
Haaland looked set to register his fourth hat trick of the season, with both goals coming in the first half.
He didn’t manage that but his latest double moved him up to 17 league goals, which is just six fewer than Mo Salah and Son Heung-min required to share the Golden Boot last season as joint leading scorers.
Haaland, who failed to find the back of the net in City’s 1-0 loss at Liverpool last week, opened the scoring after 22 minutes.
Ederson’s long clearance reached the run of the striker and, with Brighton goalkeeper Robert Sanchez stranded outside of his goal, Haaland overpowered Adam Webster and rolled the ball into an empty net.
Haaland got his and City’s second two minutes before halftime after referee Craig Pawson reviewed a challenge from Lewis Dunk on Bernardo Silva and awarded a penalty.
Haaland stepped up and powered a low shot past Sanchez, which was the club’s 600th league goal under Pep Guardiola.
Just as City fans might have been wondering how many goals their team would rack up in a latest rout, Brighton reduced the deficit.
Riyad Mahrez looked set to add to the home team’s lead but his tame shot was saved by Sanchez, which allowed Brighton to break. Solly March laid the ball off to Trossard just outside the penalty box and he unleashed a low drive that beat Ederson at his near post in the 53rd.
Trossard could have equalized later when running through on goal – but his shot from a tight angle was saved.
Brighton paid the price for that missed opportunity when De Bruyne made it 3-1 in the 75th with a superb 25-yard shot that curled into the top corner.