An impost of 60kg is tempering Pukekohe trainer Richard Collett's confidence that his talented mare Untamed Diamond can make it back-to-back wins in the Listed Legacy Lodge Sprint (1200m) at Te Rapa on Saturday.

He’s risen from being an orphan foal to being acclaimed as the world's best sprinter with career earnings of more than $7.8 million. They could be making a movie about the rise and rise of champion five-year-old Redzel.

Untamed Diamond wins 2017 Legacy Lodge Sprint Listed NZ$50,000 at Te Rapa (NZ), 1200m.

Untamed Diamond gained an invaluable black type victory at Te Rapa and connections will now raise their sights with the mare.

Untamed Diamond has further enhanced her value with her most recent Australian performance.