Major League Record Sixth Grand Slam of the Season On this day, in 1987 Don Mattingly set a Major League record with his sixth grand slam of the season to lead the New York Yankees to a 6-0 victory over the Boston Red Sox. September 29, 1987 Sport: Baseball Trivia What Are the Five Events That Make Up the Modern Olympic Pentathon? Which Nations Won the Gold, Silver and Bronze Medals the Last Time Baseball Was an Olympic Sport? sports in this article Baseball tags in this article Fan On This Day SportsEngine