Simon Wormull was left ‘absolutely devastated’ after Burgess Hill Town’s 1-1 home draw with Lewes on Monday all but confirmed their relegation from the Bostik Premier.
The Hillians thought a priceless win was secured after Dan Beck gave the hosts the lead on 78 minutes.
But Olajuwon Adeyemo’s strike two minutes from time saw the points shared and effectively doom Hill.
Wormull’s side travel to fourth-from-bottom Wingate & Finchley on Saturday, who moved out of the drop zone thanks to a 2-1 away win at Haringey Borough on Monday, looking for a miracle.
Hill have to overturn a 14 goal deficit between themselves and the Blues, and hope third-from-bottom Whitehawk fail to get a result at home to Corinthian Casuals.
Speaking to Your Instant Replay, Wormull said: “I’m absolutely devastated. I think there was only one team who wanted to go out and win the game today.
“Obviously for us it had more importance but I thought from the first minute we really set our intentions out.
“I think if we take our chances in the first-half we go on to win the game handsomely but it just wasn’t to be.
“We got our noses in front but it was fine lines. You make a mistake and you get punished for it.
“I’m just devastated for the fans and the club because it give us a real up-hill battle next week.
“We’ve got to win next week and that’s going to be difficult in itself.”
The visitors had the games first chance on four minutes. Ex-Hillian Kieron Pamment got himself into a good position but curled his effort over the crossbar.
Hill’s first sight of goal saw Aaron Smith-Joseph wonderfully bring the ball out of the sky, but his strike was high, wide, and not at all handsome.
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The Hillians had two great chances before the half-time break. Joe Felix did well to find himself some space on 36 minutes but his driven effort was just wide of the target.
Five minutes later and Ross Murdoch was agonisingly close to tapping home from close-range from Beck’s low cross across the six-yard box.
Four minutes into the second-half and Hill thought they had the lead but Smith-Joseph’s strike was blocked on the line by the Rooks’ Thomas Day.
On 69 minutes Lewes keeper Lewis Carey did well to tip Beck’s header over the crossbar.
The Hillians were finally rewarded for their persistence with 12 minutes of the game to play. Smith-Joseph did well to whip in a perfect cross for Beck to head home, sparking joyous scenes at the Green Elephants Stadium.
With two minutes to go Hill were dreaming of pulling off the great escape, but their hearts would be broken.
Sub Charlie Bennett conceded a free-kick in a dangerous area. From the set-piece Adeyemo got the faintest of touches to steer the ball past home keeper Josh James and crush the hopes of the Hill faithful.
Wormull added: “I’m bitterly disappointed we’ve essentially gone down today. It’s going to be difficult to win the game (at Wingate & Finchley) 8-0.
“We’re going to go and give it a go. You never know what happens.
“You get yourself two early goals and anything could happen.”
On Good Friday the Hillians travelled to play-off chasing Carshalton Athletic and fell to a 2-0 defeat.
Hillians: James, Kipeya-Bonno, (Bennett 59), Cadman, Wilson, Toure, Jonah, Felix, Harding (Ryder 65), Murdoch, Beck, Smith-Joseph. Unused: Tuck, Correia, Malleret.