Basically its to win a contest as you're last the one standing. Came to phrase after Steven Bradbury's inspirational gold medal at the 2002 Winter Olympics Speed Skating event, when all other contestants crashed out leaving im as the winner!
Robbo was struggling in last place at the Gunamundra Annual Billy Cart race, when a huge bull stormed across the path and stopped, causing the 5 billy carts in front to veer off the track in to the scrub and out of the race. Crowd were cheering "Do a Bradbury" as he crossed the line as the victor!
Aussie slang for underwear
Getcha bungers off sweetpea