Brighton crashed to their worst Premier League home defeat to leave themselves in serious relegation trouble as Bournemouth ended their recent slump in style.
Goals from Dan Gosling, Ryan Fraser, David Brooks, Callum Wilson and Junior Stanislas secured a thumping 5-0 victory for the visitors.
It was only the Cherries' second win their last 10 matches, but it took them past the 40-point mark to end any lingering fears they had of being dragged into trouble.
For Brighton, though, the problems are mounting, their run to the FA Cup semi-final masking dreadful form which has seen them collect just eight points since the turn of the year.
Their only saving grace was a defeat too for 18th-placed Cardiff, but Neil Warnock's side will travel to the Amex Stadium on Tuesday night for a crucial match knowing victory will cut the gap to just two points.
Brighton will also be without mercurial winger Anthony Knockaert for that game, and the two that follow, after he was sent off for scything down Adam Smith.
Worryingly, Chris Hughton's side simply do not look like scoring. They have drawn a blank in their last four matches and in that time have mustered only five efforts on target.
This was the first part of a crucial home double-header, and it went spectacularly wrong.
Joshua King has already put two presentable chances wide before Bournemouth took a 33rd-minute lead thanks to some fine interplay coupled with Brighton's poor defending.
Brooks found Gosling in the area and the midfielder played a neat one-two with Wilson.
Any one of the three players could have tucked the ball away with the Brighton defence nowhere to be seen, and it was Gosling who applied the finishing touch for his first goal of the season.
Tempers flared at the start of the second half with Florin Andone and Chris Mepham getting in each other's faces and earning a booking apiece from referee Kevin Friend.
And the mood around the Amex worsened moments later when Wilson fed Fraser, who reached the edge of the box and somehow looped his shot over Mathew Ryan and into the top corner.
Knockaert received his marching orders for a nasty foul on Smith in the corner and soon after Brooks ended any remaining home hopes when he played a one-two with Fraser before slamming the ball past Ryan.
Wilson got in on the act with eight minutes remaining, cutting in from the left and rolling the ball home, and substitute Stanislas struck in stoppage time to cap a stunning win for the visitors and leave Brighton in a whole heap of trouble.