Hornchurch boss Mark Stimson is hoping a large, noisy home crowd can help them gain promotion to National League South on Monday.
Urchins host Cheshunt in the Isthmian League Premier Division play-off final, after a last-gasp 3-2 win at Enfield Town in midweek.
Liam Nash netted a 90th-minute winner, moments after Sam Higgins had got Stimson's men back on level terms.
And Stimson said: "We had a fantastic following, I'm told over 400 Hornchurch fans were there which is great numbers for a Wednesday night.
"We need them on Monday to bring their nearest and dearest to create a good atmosphere and get that feeling again.
"It's on the day, both sides will create chances, it's who takes them and who has the rub of the green who will be winners.
"Fingers crossed it's us. It's a good one to look forward and we need the fans behind us again."
Having finished the season in fourth place, following Saturday's 2-1 home loss to Wingate & Finchley, Urchins fell behind six minutes before half-time at Enfield.
Tom Wraight was stretchered off just before half-time, but Nash levelled soon after the restart, only for the hosts to regain the lead two minutes later.
Higgins squared matters on 87 minutes, though, and Nash won it in front of the travelling Hornchurch fans.
Stimson added: "We trained on Monday and Lewwis Spence went down with a sickness bug on Wednesday morning, so we went without our captain and left-back (Remi Sutton).
"It was a nightmare injury to Tom. I didn't see it as nasty, it was two honest lads going for a 50-50, but he went to hospital and we're hoping it's not fractured or broken.
"It was a nasty gash and needed treatment and given the emotions of that, full credit to the boys. Every player was outstanding.
"To be a goal behind, equalise, go 2-1 down and then get back to 2-2 late in the game, thinking we've probably got extra time. To score a late, late goal to get the win was fantastic.
"We conceded, we had to regroup. It was a test but the boys came through, they didn't give up.
"We were asked a lot of questions, but Sam Higgins scored a corker with a great piece of skill, he has got that, and Nashy tucked the winner away well."
Cheshunt snatched a last-minute 3-2 win of their own at Bishop's Stortford and Stimson expects another emotional 'rollercoaster' on Monday.
"To get the win and get to the final on Monday is something to be proud of and to look forward to. It's another tough challenge.
"The longer you do this job, the more it happens. It's a rollercoaster and you have to strap yourselves in and be ready, try not to get too carried away.
"Given the history of the four clubs you'd think it would be Bishop's Stortford v Enfield in the final.
"But Cheshunt and Hornchurch are making more of their own history now, with their run to the fifth round of the Trophy this year and us winning it last year."
Urchins fans will be hoping it's their favourites writing another chapter next week.
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