"Go Trent," yells Sarah Walker as Trent Jones blasts down the starting ramp at the start of the Vector Arena BMX track.
"Stay on, stay on," Walker yells.
BMX is all about getting to the front - and staying on. Jones does, winning his heat. He blasts through the finish line then cannons into a huge crash pad at high speed, bringing an electronic scoreboard tumbling down on top of him. He is extricated and scoots off, seemingly unharmed.
New Zealand's silver medal hero from the London Olympics, Walker isn't surprised by Jones' big post-finish smash.
"Even I can't stop in time, and I'm not going as fast as them."