Junior middleweight Patrick Day, who required emergency brain surgery after suffering a 10th-round knockout at the hands of prospect Charles Conwell on Saturday night, remains in a coma and is in extremely critical condition, according to a statement released Sunday evening by promoter Lou DiBella.

"Patrick Day suffered a traumatic brain injury during his bout on Saturday night," DiBella said in the statement. "He was rushed to Northwestern Memorial hospital where he underwent emergency surgery. As of Sunday evening, Patrick is in a coma caused by the injury and is in extremely critical condition. On behalf of Patrick's team, we appreciate the outpouring of support, prayers, and offers of assistance from all corners of the boxing community.

"Updates will be provided as circumstances change. In the meantime, we ask that the privacy of Patrick and his family be respected during this difficult time."

Conwell, a 2016 U.S. Olympian from Cleveland, dominated the fight at Wintrust Arena in Chicago, dropping Day with right hands in the fourth and eighth rounds before landing two rights and a left hook that knocked him out in the 10th round, causing referee Celestino Ruiz to wave off the fight at 1 minute, 46 seconds.

Day, 27, was down for several minutes while receiving medical attention and was eventually taken out of the ring on a stretcher and rushed to the hospital. Day remained unconscious as he was taken to an ambulance and then suffered a seizure before arriving at the hospital's emergency room for treatment, according to sources.

At some point after arriving at the hospital, Day, who was given a breathing tube, went into a coma, according to a source with knowledge of Day's condition.

Day (17-4-1, 6 KOs), of Freeport, New York, suffered his second defeat in a row following a 10-round decision loss to emerging junior middleweight contender Carlos Adames on June 28. Conwell improved to 11-0, with eight KOs.

In 2012, Day was the New York Daily News Golden Gloves champion, USA Boxing welterweight national champion and Sugar Ray Robinson Outstanding Athlete award recipient. He was also a 2012 U.S. Olympic alternate.

Saturday's bout was on the undercard of former undisputed cruiserweight world champion Oleksandr Usyk's heavyweight debut, a seventh-round knockout victory over Chazz Witherspoon.