Patrick Day suffered a 10th round knockout in Chicago on Saturday.The American received medical attention in the ring, left on a stretcher, and had seizures en route to a nearby hospital.He underwent emergency brain surgery and is in a coma.Visit Business Insider's homepage for more stories.A 27-year-old American boxer was knocked out in the 10th round of a fight, left the ring on a stretcher, and is now in a coma.Patrick Day, from New York, was competing against Charles Conwell on Saturday, October 12 in Chicago's Wintrust Arena, an event headlined by Oleskandr Usyk's heavyweight debut against Chazz Witherspoon.Day was dominated by Conwell, knocked down by right hands in the fourth and eighth rounds, and then knocked out in the 10th, according to ESPN.The Athletic's boxing expert Mike Coppinger tweeted at the time that "Day was unconscious after [his] head hit the mat," adding that Chris Mannix on DAZN said an "oxygen mask was applied as he left [the] ring on a stretcher." A breathing tube was used at hospital.Patrick Day is undergoing surgery, I'm told, after KO loss to Charles Conwell tonight in Chicago. Day was unconscious after head hit the mat, and @SIChrisMannix reported on DAZN that Day was using a breathing tube at hospital. Oxygen mask was applied as he left ring on stretcher' Mike Coppinger (@MikeCoppinger) October 13, 2019ESPN reports that Day was on the canvas for several minutes where he received medical attention.He was taken to Northwestern Memorial Hospital in an ambulance, a three mile drive from the arena, but reportedly suffered seizures before he arrived.Day then went into a coma, though ESPN says it is unclear if this was medically-induced. He also had emergency brain surgery.Matchroom Sport group managing director Eddie Hearn, who organized the event, offered prayers on social media.Deepest prayers with Patrick right now ' https://t.co/affwhEXeXD' Eddie Hearn (@EddieHearn) October 13, 2019Heavyweight debutant Usyk won the main event, knocking Witherspoon out in the seventh round.Join the conversation about this storyNOW WATCH: Statistics tell us today's NBA teams would beat the 1996 Bulls Click here to read full news..