Ashley Barnes struck 10 minutes from time to put Bristol City to the sword and continue league leaders Brighton's fine start to life in the Championship.
For 80 minutes, the visitors were frustrated by an inspired David James.
City's former England keeper pulled off a string of saves, the best of them a stunning double stop to deny Craig Noone and Craig Mackail-Smith.
Barnes ended James's resistance, though, following up Mackail-Smith's parried shot to drill in the winner.
The win maintains Brighton's fantastic start to the season following their promotion from League One and was secured without new signing Vicente Rodriguez, who did not even feature on the bench.
Not that the visitors missed him, despite a sluggish start that saw Marvin Elliott and Neil Kilkenny go close for the hosts.
Mackail-Smith and Barnes were a constant thorn in the side of Bristol City, and the former Peterborough striker forced James's first save of the afternoon with a long-ranger on 34 minutes.
It was a far less conventional save from James on the hour, though, when he parried Noone's shot, before spreading himself to deny Mackail-Smith on the follow up from point-blank range.
James then tipped an effort from Gary Dicker over the top, but the former Liverpool man was finally beaten 10 minutes from time when his defence failed to deal with a corner.
Inigo Calderon headed the ball back into a crowded goalmouth and although James saved Mackail-Smith's initial shot, the veteran was helpless to prevent Barnes smashing the rebound high into the net.
Brighton were still grateful to a smart save from Kapser Ankergren in the closing minutes from Brett Pitman.
But they held out for a fifth win from their first six games, a run of form in marked contrast to the Robins who lie 20th with five points.