Alright, there was a post before that was about there being bugs etc in arena, I've found it while playing on my twink, instead of facing the enemy turn around facing the directly opposite direction, and auto run into the wall (Before the elevator goes up) upon reaching the top you will walk through the fence closing you in, allowing you to get a jump start on the enemy team, Once you've left the starting thing you can walk through enemy fence etc.
Try to get a jump on the competition before it's too widely known, and fixed

Enjoi!