Do you remember in school when people who didn't want to fight, but had been somehow placed in this situation, would be quickly surrounded by a baying crowd, which if the two participants were not aggressive enough would attempt to force the issue by goading them first and then pushing one of the fighters in the back.
That happened to me at school. I was having a tussle with my friend (all in good fun) when word spead that we were having a fight. We were swiftly surrounded by the bigger kids and were both a little bit scared.
Fed up by our lack of enthusiasm for the fight someone pushed me hard in the back. I flew forwards and somehow my forehead landed on my friends nose breaking it and impressing the crowd.
From then on I had a reputation as one of the better fighters in my year.