This happened many years ago in our old dojo and it still bites back at me to this day.
It was a wet,cold night so not many people turned up to trainig (the roof was leaking) so my sensei decided to have some fun, he introduced us so sock fighting for those of you who dont know its were to people wrestle with each other on the mat atempting to pull the others persons sock off (they wear only one sock and you arent alound to stand up) well after a few successful bouts against other students my sensei decided to take me on. To make it more exciting we added in "win by submission" as well. I got my ass kicked the first two rounds (painfully) and then on the third his index finger happened to slip into view admist all the confusion and i simply bent it into its self squeezing the tip up towards his knuckle.
I was stoked. Sensei wasnt but he congratulated me on my abilitly to take any pathic opportunity and turn it to my advantage.