His final major league at bat came on September 29, 1989 when the Toronto Blue Jays were hosting the Baltimore Orioles. There was a great deal of attention paid to the game, as it was the middle game of a three-game series that would decide the winner of the American League East. The Baltimore Orioles had beaten even the most optimistic expectations and were in first place for much of the 1989 season. Baltimore needed to win three games against Toronto to enter post-season play. Baltimore had lost the first game. In Mazzilli's final at bat during the second game, he hit a double to center field.