The Australian had struggled with injury problems with her mount, California, beforehand and had not even been confident of making it to the start-line.

But once there, they rode two clear rounds including the fastest jump-off time of 32.07sec.

Bassem Mohammed rode Gunder to a Qatari silver medal with a 35.47 clear run in the jump-off.

Darragh Kenny of Ireland and Cassini Z had a fence down but still managed third place and a swift time of 30.87.

Tops-Alexander also won the event in 2011 and 2012.