Midway through this bonkers soccer game, I ran into one of the fiercest D.C. United fans I’ve ever met, the kind of guy who stays up nights planning new ways to show his love for the black and red.

“I want to go to an away game with Christos,” he said with a grin. “I hope they win.”

I think he was joking. But you could forgive him for getting intoxicated by those Baltimore kids in neon green, the amateurs sponsored by an Anne Arundel County liquor store, the college stars who now have day jobs, haven’t had a real training session in forever and gave the Washington pros everything they wanted for 80 minutes. I sort of felt like a Christos FC fan this month too; “I think we all kind of were,” said United Coach Ben Olsen.

The 4-1 final score wasn’t what anyone will remember from this game. What they’ll remember is the 23rd-minute blast from Mamadou Kansaye that gave Christos a 1-0 lead, and sent the supporters streaming down a hill at the Maryland SoccerPlex so they could rage with their younger selves.

“I’m going to have a heart attack” one screamed as he emerged from the mosh pit.

“We’re burning the place down!” someone else promised.

“Thrown beer, thrown hats, broken glasses,” said Eric Breach, a player for the Christos over-30 team who was in the middle of the mayhem. “It was a pile of chaos, a good pile of chaos. It was absolutely nuts. It was awesome.”

And it was. Look, we just finished watching an NBA Finals that was beautiful in its own way, but crushingly predictable. At the start of the season, you’d have guessed the Warriors would beat the Cavaliers in the Finals, probably in five games. That’s what happened. Knock me over with a bottle of Moet.

The U.S. Open Cup, like the best cup competitions, is shot through with the promise of a surprise. And so at the start of this tournament, you probably wouldn’t have guessed that Christos would beat two pro teams, earn $15,000 as the last amateur team standing, raise nearly $9,000 by crowdsourcing its travel costs, sign a huge apparel deal with Adidas (“basically, they gave us the world,” one Christos official said) and earn so many media requests that by Tuesday morning there were no players left to fulfill the last podcast entreaty.

You wouldn’t have guessed, either, that thousands of fans would pour into this suburban soccer field, so many that they were lined up at the gates for most of the first half, just trying to get inside. The crowd of 5,286 was something like 10 times bigger than the biggest crowd Christos had played in front of. At least six buses of fans poured in from Baltimore, and there were hundreds of those neon green folks tailgating a couple of hours before this fourth-round Cup game.

“A third of these people I don’t even know,” said Darius Taylor, the club president, as he surveyed the Baltimore contingent.

“This is spectacular,” said Bobby Wagner, one of the original members of the club.

“When I woke up this morning, I had chills on my arms,” said Mike Libber, another longtime leader.

“They blew up in an instant,” said Jesse Hoffman, a friend of Christos right back Collin Fisher. “This is all Baltimore pride right now. There is no other professional soccer team in Baltimore. And they aren’t even professional.”

That was part of the charm for the fans in Orioles and Ravens and Maryland flag gear, the fans who screamed “Oh!” during the national anthem, the fans who spun around in delight when Christos took that first-half lead. Baltimore is a natural soccer market, they said, the leading U.S. market in Premier League ratings, a place that deserves a pro team. For now, this was the next best thing.

“I mean, look around, and this is an amateur team,” said Don Colburn, a Baltimore soccer fan, gesturing at the sea of green.

HEY, DON’T GET SCARED, THEY’RE JUST AMATEURS,” his friend Jonathan Peak hollered toward the United supporters.

There were also the kids who were coached by Christos players, which only added to the family reunion vibe. (“Oh my gosh, I see so many people I know!” yelped Adriana Carrillo as she entered the gates. “I know them as coaches,” said 13-year old Liam McCaffrey. “To see them now playing against professionals, it’s very cool.”)

And then there were members of Christos family, those 30- and 40-something guys who came to this game from Cincinnati and Delaware and mostly Baltimore. The shirts they wore listed the names of all 287 “brothers” who have played for the club; they had 500 shirts made this week and they were all long gone by Tuesday night. The Christos veterans said they expected a competitive match, but when their side went ahead in the first half — and stayed even through 80 minutes — there was the kind of jolt that infuses these events with magic.

United was bigger and faster and fitter in the end. And after the torrent of late goals, the Christos supporters stood near the same spot they had partied and sang their anthem: “I know I am; I’m sure I am; I’m Christos ’til I die.”

“Indescribable,” Libber said of the night. “It’s just overwhelming.”

“We’ll do it again every week if they’d let us,” Ken Suter Jr. said. “We’ll be back.”

Before that can happen, players have another game next week, a regional final in a different Cup competition against a team called the Lansdowne Bhoys. And before that, there’s work on Wednesday morning

“At 7:30,” Christos’s Cody Albrecht said late Tuesday night. “Pray for me.”