Brighton 4-2 Tottenham - Highlights
Tottenham, this season's early pacesetters, remain in fifth spot after losing 4-2 despite threatening an astonishing comeback from 4-0 down against Roberto De Zerbi's Brighton.
Jack Hinshelwood finished with brutal power to put the home side ahead following a weaving run from Joao Pedro along the edge of the penalty area.
Brighton doubled their lead from the penalty spot in the 23rd minute through Pedro, who took full advantage after Dejan Kulusevski was penalised for a pull on Welbeck.
Brazil forward Richarlison twice had the ball in the net after the break but both times he was ruled offside.
Pervis Estupinan stretched the lead with a thunderbolt from 30 yards in the 63rd minute and Pedro scored a second penalty 12 minutes later.
Alejo Veliz grabbed what appeared to be a consolation goal in the 81st minute but it galvanised the visitors.
Ben Davies headed home Pedro Porro's deep cross as Spurs threatened to cut through every time they poured forward, with Pierre-Emile Hojbjerg hitting the post during nine frantic minutes of stoppage time.
But Brighton withstood the intense pressure to take all three points.
"I am really lucky to be this coach of this team with these players," De Zerbi told the BBC. "I am very pleased with the passion they have, they have everything.
"You can't forget we are Brighton. Sometimes they forget we are Brighton. We are not Manchester United, Manchester City, Newcastle or Arsenal, we are still Brighton."