When Baseball Was Pure.

http://en.wikipedia.org/wiki/Ten_Cent_Beer_Night

"Jeff Burroughs violently reacted to a fan stealing his glove and cap, the Texas players, led by manager Billy Martin, charged onto the field with bats. A huge number of intoxicated fans, some armed with knives, chains, and portions of stadium seats that they had torn apart, surged onto the field; others hurled bottles from the stands. Realizing the Rangers might be in danger of their lives, Ken Aspromonte, the Indians' manager, ordered his players to grab bats and help the Rangers."


http://en.wikipedia.org/wiki/Disco_Demolition_Night

"White Sox TV announcers Harry Caray and Jimmy Piersall commented freely on the 'strange people' wandering aimlessly in the stands. Mike Veeck recalled that the pregame air was heavy with the scent of marijuana. When the crate on the field was filled with records, staff stopped collecting them from spectators who soon realized that long-playing (LP) records were shaped like Frisbees. They began to throw their records from the stands during the game, and the records often struck other fans. The fans also threw beer and even firecrackers from the stands.

After the first game, Dahl, dressed in army fatigues and helmet, along with a female sidekick named Lorelei and bodyguards, went out to center field. The large box containing the collected records was rigged with a bomb. When it exploded, the bomb tore a hole in the outfield grass surface and thousands of fans immediately rushed the field. Some lit fires and started small-scale riots. The batting cage was pulled down and wrecked, and the bases literally stolen, along with chunks of the field itself. The crowd, once on the field, mostly wandered around aimlessly, though a number of participants burned banners, sat on the grass or ran from security and police. People sitting in the upper deck could feel it sway back and forth from the rioters."