There is no activity that you can imagine—legal or illegal, savory or unsavory—that is not occurring on a regular basis behind some closed door somewhere in New York City. Are there regularly occurring, unlicensed, and unregulated full-contact bloody ultimate fighting competitions happening in some underground gym way up in The Bronx, for example? Of course there are. This is a metropolis, after all.

And so there we were on Sunday afternoon—maybe 50 of us in all—in a tiny storefront boxing gym way way uptown, watching men fight each other, sometimes well and sometimes not so well. Professional mixed martial arts is not legal in the state of New York for obscure reasons. So all of the fighters at all of the many MMA and jiu jitsu gyms who want to fight without having to trek out to Jersey (and who would want that?) find their way to the Underground Combat League (UCL), New York City's most prestigious and long-running quasi-legal fight circuit. They've been going for years. Four or six or eight or ten shows a year, moving around to wherever they can find space: boxing gyms, martial arts gyms, empty rooms for rent. Anywhere will do, really.

"Sometimes they put up a cage, sometimes it's in a ring, sometimes just on mats," explained my unofficial tour guide, Jim Genia, who wrote a book about the UCL that you should buy right away. "Once they had it in a mosque. They just rented out the space and laid down mats."

The New York law doesn't say anything about amateur MMA fights, so the UCL simply operates on the premise that they are legal—even while keeping fight locations secret, maintaining a carefully managed invitation list, and generally staying faithful to the "underground" part of its name. "This shit is probably legal, or could theoretically be ruled legal should such a case ever go to court, and definitely should be legal, by why take risks?" is the overall tenor of the UCL's operations.

"Rage," a bald and goateed former fighter who now promotes UCL shows himself, stressed to me that they always try to keep the fights as professionally run and fair as possible. There are same-day weigh-ins to prevent unhealthy weight-cutting; they call the gyms to "check out" prospective fighters to make sure they're legit; they send fighters to the health center out in Brownsville where they can get free physicals.

"Some of these dudes are having a hard time," Rage explained. "Some don't have no money, some are in school." These guys are all doing their best, under the circumstances. They just want to fight. Fight fight fight.

So let's fight. On Sunday, the UCL set up a small Bronx boxing gym in a storefront that had the white overhead paneling and fluorescent lights of something like an insurance office. It easily could have been one, save for the cut-out Ring Magazine pages taped to the walls and the single, small boxing ring set up towards the back of the space. A couple dozen folding chairs had been set out in crooked rows amid the hanging heavy bags. A tiny little girl in pink pants and a Hello Kitty hat had a front row seat. Spectators were invited to stand in three-foot-wide spaces on either side of the ring, too; there were no real barriers between audience and fighters and fight team entourages, all of whom showed up in proud screenprinted hoodies. "Twin Towers Wrestling." "Radical Jiu Jitsu." "Sadistic Athletics." "Team Asylum— Asylum Inpatient." The screenprinting was misleading. Outside of the ring, it was all very friendly.

The first bout pitted a big, pot-bellied heavyweight wrestler named Nick (who sported a USA-colored singlet) against Rashid, a man with the size and physique of an NFL linebacker and a fitting nickname: "Smash." At the bell, Nick strode forward and tried to grab his opponent. He failed. Rashid smashed him in the temple with a right hand and that was it—about six seconds from bell-ringing to Nick splayed out unconscious on his back. He got up, though, and received a polite round of applause.

One fight, one minute! Keep it moving! Adrion, a fighter from Twin Towers Wrestling, faced Marwin, a jujitsu fighter who had a reddish goatee and many inscrutable tattoos across his belly. The bell rang. Marwin ran straight out and slammed a kick into Adrion's side, which elicited an audible "crunch." Then he swung around, wrapped his legs around the wrestler's waist and his arms around his throat and pulled him to the ground and choked him out—all within four seconds. Two fights, two minutes!

But Adrion was not getting up. He'd fallen down while getting choked. His leg had bent at an odd angle, and his femur snapped clean in half. He laid in the ring in a pained heap. He didn't cry, but he had that look of agony on his face that adults who are too macho to cry get when they're experiencing pain that makes them wish they could cry. Later, a guy who'd been recording the fight on his phone showed us the replay: Adrion swung around with his opponent on his back, one leg planted awkwardly, and then it all came crumbling down.

[There was a video here]

"That's the worst injury that's ever happened in the UCL," Jim assured me. (A video of the fight popped up today on Youtube. Watch it at left, at your own discretion.) That it came not as the direct result of a strike but from an awkward fall was somehow reassuring. The same injury could happen in soccer, for god's sake. There was no medic in the house, so eventually they loaded the injured fighter onto a big white plastic table with the legs folded up and slid him out of the ring so the fights could go on.

"They gonna have to take him to the hospital," speculated one ringside observer as Adrion's leg flopped in an alarmingly unnatural direction, making it appear as if he'd grown an extra joint. "They can't put him in a cab like that."

Paramedics were called, and the fights went on. An evenly matched one, this time: Josh vs. Chad, two jujitsu fighters who both seemed to know what they were doing. We, the nominal media invitees, were all standing right beside the ring, along with the cornermen and all of guys from Josh's gym. They shouted advice the entire time, sometimes leaning in to shout inches from Josh's ear as his head poked through the ropes during a chokehold. ("Pass, Josh!" "Hit him, Josh!" "You gotta hit him in the face, Josh!") Josh had no shortage of strategic advice. One corner shouted, "Hey, he's hitting in the back of the head!" From the other corner, inches away from the grasping fighters: "No it's not, that's the temple. I can see it."

Throughout all of the matches the radio stayed on, playing a decidedly un-testosteronish mix of old school hip hop. I heard Busy Bee and Kool Moe Dee as Chad took a decision win over Josh. When they'd finished, two grapplers went in and locked up and started rolling around.

As they fought, the paramedics arrived. They made their way right past the ring and into the back room, where Adrion waited on his folding table of pain. And immediately after the paramedics, a police officer came in. Then another. And another. Then a whole goddamn mess of cops came in, just kept coming, as if unloading from a clown car parked outside. Soon there were upwards of a dozen uniformed beat cops in the gym, as the (legal? Illegal?) unlicensed fight raged on in the ring. The cops filed past the table selling "Underground Combat League" T-shirts, past the spectators in the folding chairs and the Hello Kitty girl in the front row, and past the shouting cornermen, who took little notice of the sudden police presence.

The cops did not seem to be doing anything in particular. They made no move to break things up; they did not whip out their nightsticks or guns or handcuffs and start demanding, "What's going on here?" A few even watched the ongoing fight with interest. The rest of them seemed to be as confused as I was as to why they were. Does it take a dozen cops to escort a stretcher from an ambulance into the back of a boxing gym?

"It's the Bronx," Jim said, shrugging.

After about 10 minutes, the paramedics wheeled out the injured fighter on an actual stretcher to another polite round of applause, and all the cops filed on out, and that was it. The grappling match had not been disrupted in the least. It was no Supreme Court ruling, but it seemed an encouraging sign for underground MMA aficionados.

All that was left after the police's exit march was the final bout, in which "Smash," barely winded by his five-second KO in the first bout, came back on to fight Miguel, an even more overmatched opponent. Miguel was short and round and—while possessed of a good fighting spirit—also a walking demonstration of why fighters should never fight in the heavyweight division simply because they're fat. Smash held Miguel out at arm's length with one hand and punished him with the other, like a wayward little brother. He lasted a few minutes before the ref called a TKO, which could be considered a moral victory for Brave Miguel. Then he rolled out of the ring, T-shirt ripped down to a V-neck, nose and chest bloody, with huge red mat scars on his neck, and made his way to the bathroom to wash his face, looking like a tired—oh so tired—man coming home from work.

His girlfriend could not have been pleased. But he did it. At least he did it.

Photographs by Anil Melwani.