Alexis Mac Allister netted twice as Brighton heaped more misery on Everton and their under-pressure manager Rafael Benitez at Goodison Park.
The Toffees have won just one of their last 12 Premier League games after this latest setback with Dominic Calvert-Lewin's penalty miss compounding a bad afternoon.
Argentine Mac Allister opened the scoring for Brighton just three minutes in and Dan Burn headed home their second. Calvert-Lewin smashed a penalty against the bar before Anthony Gordon did reduce the deficit early in the second-half.
However, Mac Allister's second goal made it 3-1 to Brighton, who held on to climb to eighth despite another from Gordon late on.