Ross Allen's hat-trick gave Guernsey FC a 3-2 win over Hastings United in the first round of FA Cup qualifying.
The winner came courtesy of Allen's injury-time penalty after Hastings defender Kwasi Fobi-Edusei handled.
Allen opened the scoring after getting on the end of Dom Heaume's pass, but Bailo Camara equalised for Hastings.
The striker's second came after a quick free-kick only for Hastings to level through Danny Ellis before Allen sealed a dramatic and famous win at the death.
"I'm really proud of the boys," said manager Tony Vance.
"They are the ones on the pitch who make things happen. We were good going forward and generally good defensively."
Hastings United made it through to the third round of the FA Cup last season, eventually losing 4-1 to Championship side Middlesbrough at the Riverside.
Guernsey FC, founded in 2011, had to meet a set of financial conditions imposed by the Football Association to enter the FA Cup and FA Trophy this season.