Former Brighton captain Danny Wilson made a triumphant return to his old club as his Bristol City side romped to a 4-1 win at the Withdean Stadium - their first league victory for six games.
They destroyed the home team's hopes of returning to winning ways with three goals in the space of 18 minutes in the first half.
Luke Wilkshire put City ahead on 26 minutes with a classic counter-attack following a Brighton free kick. Christian Roberts released the former Middlesbrough midfielder to slot his second goal in as many games.
Wilson's attacking team selection continued to pay off as Lee Miller, returning from injury to debutise for unwell top scorer Lee Peacock, headed in a Kevin Amankwaah cross five minutes later.
Another right wing cross by Amankwaah was headed in off a post by Aaron Brown on 44 minutes as Bristol threatened to repeat the five goals they scored in the FA Cup at Bradford Park Avenue last week.
Leon Knight threw Brighton a lifeline in first-half stoppage time from a penalty awarded when Miller handled a corner, to raise his tally to 14 for the season.
Brighton, with Mark Yeates making his league debut on loan from Spurs, dominated the second half but could not find a way past City's defence.
The visitors sealed the win with six minutes left when skipper Matthew Hill headed in a controversial fourth from Wilkshire's cross.
The linesman had his flag raised, but quickly put it down and the goal was allowed to stand, despite Brighton's protest.
Brighton have now taken one point from the last 15 and Mark McGhee, appointed as their eighth manager in six years last month, has a tough job on his hands to rescue their promotion challenge.