Kyle Hay travelled to Boston with a group of friends to watch the Maple Leafs take on the Bruins at the TD Garden on May 4 in the second game of the current playoff series.
"It worked out that the game was actually on my birthday as well, so we were all pretty pumped about it," Hay told CBC News in a recent interview.
The 23-year-old remembers hearing a group of rival fans throwing peanuts and empty beer cups at him and his friends.
Hay, who was wearing a Leafs jersey, as well as a blue mask and mohawk, said his group didn't return the taunts. He said he and his friends focused on celebrating after each goal.
The last thing he remembers is someone hitting him.
"I didn’t see it coming or anything like that," said Hay.
The blow knocked him out. Hay said he was out for about three to five minutes.
Hay now has three staples in his head. He is awaiting the arrival of his medical bill from the U.S.