A mixed martial arts fighter remains in critical condition after he suffered a traumatic brain injury and collapsed windpipe Saturday night in a professional fight at the Kent Freeman Arena in Detroit Lakes.

Forum News Service reports that Dan Kiser was injured after his opponent landed a left hook then "put a rear naked chokehold" on him. The referee stopped the fight after seeing Kiser was knocked out. WDAY reported that Kiser was still unresponsive after the bell rung and an ambulance was called. He was rushed to a hospital in Detroit Lakes, then to Sanford Medical Center in Fargo.

Mixed martial arts, known among fans and fighters as MMA, is described as a full-contact combat sport that allows the use of both striking and grappling techniques, both standing and on the ground. It is derived from a variety of combat sports and involves the use of martial arts such as kickboxing, judo, and karate.

“Dan did suffer a traumatic brain injury and had surgery the night of the fight to help drain fluid and relieve pressure and swelling on his brain,” said Ben Pherson, who runs MN MMA News, a website devoted to mixed martial arts in Minnesota.

On Pherson’s website, Kiser’s father, Dan Kiser Sr., said his son's condition has improved.

“He is out of the woods as far as fighting for staying here on earth; he turned that hard corner,” the elder Kiser said. “Now, he’s fighting for things like how much rehab he’s going to have to do. The word the doctors use is ‘deficits.’ How many deficits will he have when this is done? That’s what he’s fighting for now.”

Kiser’s manager, Jeremy Bjornberg, said his fighter had been taken off life support and was breathing on his own. But Bjornberg cautioned that Kiser’s condition remains uncertain.

"It’s just so early to say what’s going to happen and what isn’t,” said Bjornberg.

The website MixedMartialArts.com said that Kiser currently lives in Wisconsin and trains at Spartan Martial Arts in Oakdale.

The family has set up a GoFundMe site to raise money to help Kiser and his family. It says that Kiser "...has a wonderful fiancée and two beautiful little girls that have supported his fighting career as well, and will now be on this road to recovery with him." The site had raised $4,600 as of Friday morning.