(CNN) Boxer Patrick Day died Wednesday, four days after he was knocked out during his bout with Charles Conwell on Saturday night in Chicago.

Day, 27, succumbed to a traumatic brain injury he suffered that night , according to a statement from his promoter, Lou DiBella of DiBella Entertainment.

"He was surrounded by his family, close friends and members of his boxing team, including his mentor, friend and trainer Joe Higgins," DiBella said in a statement. "On behalf of Patrick's family, team, and those closest to him, we are grateful for the prayers, expressions of support and outpouring of love for Pat that have been so obvious since his injury."

"All I wanted to do was win. If I could take it all back, I would," Conwell wrote. "No one deserves this to happen to them. I replay the fight over and over in my head thinking what if this never happened and why did it happen to you."

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