American boxer Patrick Day was fighting for his life in critical condition in hospital on Sunday night after lapsing into a coma following a vicious knockout by Charles Conwell the night before. The 27-year-old Day suffered a "traumatic injury" and underwent emergency brain surgery Saturday night after being knocked out by Conwell in a super welterweight bout on the card at Chicago's Winstrust Arena. "Patrick is in a coma caused by the injury and is in extremely critical condition," said fight promoter Lou DiBella.