Slaven Bilic suffered surely the worst defeat of his spell as West Ham boss as they were thrashed 3-0 at home to Brighton.
Two goals from Glenn Murray and a first Seagulls strike for Jose Izquierdo put the Croatian's future firmly back in the spotlight.
Joint-owner David Sullivan even backed his manager before kick-off, saying he would be given the opportunity to at least see out his contract until the end of the season.
But a clueless and shambolic performance, probably their most inept to date at the London Stadium, can only have set the alarm bells ringing.
A win would have catapulted West Ham into the top 10 - but instead they could be in the bottom three by the end of the weekend.
Brighton, who had previously scored just once away this season, losing three matches and picking up one draw, simply could not believe their luck.
Pascal Gross had a hand in all six of Brighton's previous goals this season, but nobody seemed to have told West Ham's defenders.
He promptly made it seven in the 10th minute when he floated a free-kick towards the head of Murray.
The striker, who hit 23 goals last term to help the Seagulls to promotion, capitalised on the non-existent marking to nod into the corner and open his Premier League account.
West Ham briefly threatened to make a game of it but Brighton merely showed them how to defend.
Manuel Lanzini's shot was deflected behind, Pedro Obiang's drive was held by Mathew Ryan and Shane Duffy made a brave block to deny Javier Hernandez.
Then Brighton, having weathered that mild storm, doubled their lead in first-half stoppage time.
Murray should have done the honours when he broke through on goal, but Joe Hart beat his his effort away.
However, when the ball eventually reached Izquierdo he cut inside on his right foot and unleashed a fierce curler which Hart got a hand to but could not keep out.
The Hammers were predictably booed off at half-time and Cheikhou Kouyate was made fall guy, with Andre Ayew sent on in his place.
How Marko Arnautovic escaped the hook was anyone's guess, although when the club record signing was finally hauled off midway through the second half he was left in little doubt about what the locals made of his display.
And moments later West Ham's misery was complete, Pablo Zabaleta tripping Murray in the area allowing the frontman to kill off West Ham from the penalty spot and pile the pressure back on Bilic.