Shoreham Football Club were left on the brink of Bostik League South relegation on Saturday.
Jake Embery got the only goal as Herne Bay ran out 1-0 victors at Middle Road.
The defeat was Mussels' 32nd from 40 league fixtures this campaign and left them 14 points adrift at the foot of the table with six games left to play.
Shoreham's relegation will be confirmed tomorrow if they lose at home to Guernsey and second-from-bottom Molesey win their match.
Even Mussels manager Sammy Donnelly concedes relegation is all but inevitable now.
He said: "It's going to be a real long shot if we are to get out of the position we find ourselves in now. The players are still positive, so am I but we have to be realistic.
"We want to end the season as strong as we can, even if we are relegated, it's about trying to end on a high.
"I've had positive discussions with a number of the squad, who I hope will stick around no matter what division we're in next season."
Embery's effort after 19 minutes would prove the difference as Herne Bay stole a 1-0 victory.
Mussels were much-improved after half-time but could not find a way through.
Shoreham are back at home tomorrow, with Guernsey the visitors to Middle Road.
Donnelly said: "This is a chance for us to give our supporters something to cheer about. We want to give ourselves a fighting chance for as long as we can, getting a victory would help us do that."
SHOREHAM: Measor; Koduah, Dunk, Tuck, Proto-Gates; Leitch, Castano, Scott; Collyer, Roddy, Baah. Subs: Bromage (Proto-Gates), Follea (Baah), Myers (Leitch), Broadbent.