SAN FRANCISCO (KRON) – Hundreds of people lined the block outside an ordinary warehouse in San Francisco’s SoMa neighborhood last weekend for an exclusive invite to the Silicon Colosseum an underground fight club with mechanical competitors.

An online invitation was sent to a list of roughly 2,000 people the night before the event. The sold-out crowd paid $30 per ticket for a chance to watch robots fighting robots.

“Ladies and gentlemen, esteemed guests and community members, investors in the future, and (of course) robots, l’m extremely excited to invite you to the first showcase of cutting-edge robotic supremacy,” the invitation read.

On the night of the event, the crowd gathered around a caged octagon. The preliminary rounds started with (human) volunteers facing off in “Taser knife fights,” slashing at each other with rubber blades attached to stun guns.

When the robots were ready, the “house robot,” a Booster T1 bot named “Booster” was lowered into the ring. Standing just under 4 feet tall and weighing 66 pounds, the boxing-glove-wearing-‘bot drew cheers from the crowd as it shadow-boxed around the ring.

In the first robo-fight of the night, Booster took on a taller K-Scale robot, knocking the roughly 80-pound, headless machine down several times. Later in the night, Booster also boxed a bipedal dog-like robot named Gladiator. Though the bipedal robot easily tipped Booster over during the match, the humanoid repeatedly won over the crowd with its ability to right itself.

Despite issues with some of the robots for Saturday’s card, the organizer behind the event, 20-year-old Bay Area transplant Verda Korzeniewski, told Nexstar’s KRON that attendees enjoyed the show.

“They loved it,” Korzeniewski said. “Somebody said it was just the right amount of weird. It spanned so many things: Robot fights, human fighting, quadrupeds versus humanoids.”

A robotics and software engineer by trade, Korzeniewski left behind his jobs in the robotics industry before focusing on her vision for the Silicon Colosseum.

“I was so addicted to robots that I gave up my entire life to do them,” she said.

Korzeniewski credited her fellow organizers for helping her pull off her second-ever robot fight night. (The inaugural Silicon Colosseum was held in July.) Shortly after the first show, she had also explained what it took to make the event happen.

“When I quit my job at a humanoid-robot company to start an underground humanoid-robot fight club, barely anyone believed in me or this idea,” she wrote on social media. “I had no money to buy robots and knew very few people who had the ability to get robots. Thankfully, I was able to find the best of the best, our rag-tag dream team. “The dream [is] still alive and ensouled in this city of madness and psychological warfare.”

Those interested in attending future robot battles are encouraged to join the Silicon Colosseum Partiful list. Korzeniewski said that she’s aiming to hold another robot fight in November; however, she didn’t reveal where the next event might take place.

“It’s an underground fight club,” she said. “You know I can’t tell you that.”