Cray Valley produced a stirring performance to defy a gap of 117 league places and force a replay in their FA Cup first round tie at League One Charlton.
The team from the eighth tier of the football pyramid held the side from five divisions above after Addicks defender Lucas Ness put through his own net in the second half.
Charlton had looked to be in control when Scott Fraser gave them an early lead but they proceeded to hit the bar and miss two big chances to add to their advantage.
That means the Millers, from the Isthmian League South East Division, earned the right to host their neighbours - the two clubs are three miles apart - in a replay.
The game had been tagged the "Greenwich Borough" derby, between a club that won the FA Cup in 1947 and one which was playing in the first round for only the second time in their 104-year history, after winning eight qualifying games to get there.
Charlton are rarely giant-killing victims, having only lost once in 21 ties against non-league opposition, and while that record remains intact they were given a huge scare, as Cray Valley could have won it in a frantic finish.
The Millers took 2,000 fans to the Valley, even though they average around 150 for home games, and those supporters feared the worst when Fraser raced through the middle of the non-league side's defence to latch on to a through-ball from Karoy Anderson - which had been cleverly dummied by Slobodan Tedic - and round keeper Sam Freeman to turn the ball in the empty net after nine minutes.
Freeman also had to produce a smart stop from Tedic to keep Cray Valley in the tie before half-time.
Cray Valley raced out of the blocks in the second half and were level within two minutes.
The excellent Sonny Black played a slick pass inside a Charlton defender and when Kyrell Lisbie - son of Charlton legend Kevin - fired in a cross, Ness could only divert it past keeper Sam Walker.
New Charlton boss Michael Appleton had made 11 changes from the team that won at Wigan in midweek but he ended up throwing on five of his more regular starters as his side strove for the win.
Charlie Kirk blazed one great chance high over the bar and the outstanding Freeman blocked from the same player as Charlton turned up the heat.
Tedic looped a header on to the bar, Chem Campbell had a penalty appeal turned down after he was brought down in the box and Freeman twice saved from substitute Miles Leaburn.
In a frantic, end-to-end, last few minutes Cray Valley, whose marathon cup run means they have only played five league games this season, dug deep to create late chances of their own with Julien Anau firing the best of them high over the bar.
The two teams will meet again in the replay with a trip to face League Two side Gillingham waiting the winners in the second round.
Cray Valley manager Steve McKimm told BBC Match of the Day:
"I can't speak highly enough of my players. They were unbelievable. We knew we were up against it, even more so when they bring the five big guns on.
"To a player they were unbelievable. At half-time I told them to believe in themselves.
"We were on a hiding to nothing but when you give belief to players anything can happen."