0832 GMT June 26 2017
The Canadian, who fought in UFC from 2009 to 2011, was knocked down five times in the first two rounds against Adam Braidwood before it was stopped, BBC reported.
He walked out of the ring but was then taken to hospital and fell into a coma.
"It is with incredible sadness, sorrow and heartbreak to report that Tim has passed away," his family said in a statement on Sunday.
"He was surrounded by family, listening to his favorite songs," they added. "We will miss him so greatly. We ask for privacy during this difficult time."
Hague beat Pat Barry on his UFC debut but went on to lose his other four fights.
He held a similar record after moving to boxing, starting with victory over Patrick Graham, then losing the following three bouts, including two knockouts against fellow Canadians, Mladen Miljas and Braidwood.