The Miami Marlins displayed a photo of Muhammad Ali on their video board Friday night indicating the heavyweight champion had died, although there had been no confirmation of his passing.
Ali's family announced his death in Phoenix more than two hours later.
Marlins President David Samson explained the premature tribute by saying he was told shortly before their game against the Mets ended that Ali had died.
"We were informed he passed away," said Samson, who declined to disclose the source of his information. "We wanted to honor him. I was informed and did what felt natural. I was not aware it had not been made public yet."
Moments after the game's final out, a photo was displayed on the video board at Marlins Park showing a triumphant Ali standing over Sonny Liston at the end of their 1965 fight. Shown in the corner were these dates: "1942-2016."
Spectators departing the ballpark applauded Ali in tribute.
Ali threw out the ceremonial first pitch in the first game at Marlins Park four years ago. At the time, team owner Jeffrey Loria called him "the most famous person on the face of the earth."