Morpeth Town chairman Ken Beattie slept in his car ahead of their FA Vase semi-final after working through the night to get the pitch ready.
Midfielder Luke Carr sealed victory for the Highway Men over Bowers and Pitsea with a 93rd-minute winner on Sunday.
"I managed to get an hour's sleep in the car at about 3am," Beattie told BBC Newcastle.
"Obviously I was nervous so I wouldn't have slept anyway, but there was so much work to do."
He added: "It's the hugest thing ever in the history of the club. It's 132 years old and it's the most fantastic thing to have happened.
"The people who have been involved in the club over the last 50 years, it's for them - they've put in so much hard work in good times and bad times and it's a fantastic achievement."
The Northern Division One side will face Hereford FC in the FA Vase final at Wembley on Sunday, 22 May.
Morpeth Town captain Keith Graydon scored the winner in the 2013 Vase final for Spennymoor Town and says nothing compares to winning at Wembley.
"I just got married at Christmas time but it's never ever going to be up there with the weekend we [Spennymoor} had at Wembley - especially winning and scoring the winning goal," he said.
"I always say it to the Mrs but I don't think she likes it when I say it."