Ballet is usually all about grace, elegance and beauty, and the audience is usually just as classy and refined as the dance, so you'd never expect to see a fight at the ballet.
Which is why the audience was astounded when Russian ballet dancer Oleg Chernasov of the Igor Moiseyev Ballet came out wearing a crazy costume and did a strange dance that looked like two kids fighting on stage.
-Via Laughing Squid