Champions three times in the past seven years, Sussex look destined for the Second Division after a dramatic collapse saw them hurtle to a 156-run defeat to Yorkshire on Saturday.
Matthew Hoggard's hat-trick was the highlight for the visitors at Hove: the former England man had Andrew Hodd caught behind then sent Dwayne Smith's off-stump flying out of the ground and finally had Piyush Chawla caught at second slip. David Wainwright took 4 for 12, meanwhile, as Sussex slumped to 83 all out.
The South Coast side, 15 points behind Lancashire, will have to beat Nottinghamshire at Trent Bridge in their final match, starting on Wednesday, and hope for other results to go their way. That seems unlikely, and a season that has seen Sussex claim the Twenty20 Cup could end in bitter disappointment.