The veteran Papua New Guinea distance runner appeared to have injured himself as he won the first XV Pacific Games track and field gold medal at the BSP Stadium tonight.
Turning the final 100m bend, Yao had the gold medal in sight and only had a last obstacle.
With the passionate crowd roaring in unison, PNG, PNG, Yao stumbled when jumping over the cross bar, hitting his foot.
Yao has two more events on his orogram and the foot injury could affect his chances.
Yao was seen hopping around after the medal presentation.