The most expensive and best-bred horse racing in Australia on Saturday was not in a feature at Moonee Valley but Zephyron's win in a restricted race at Rosehill was almost as good.

A $2 million yearling by Zabeel out of Diamond Like, the five-year-old did his early racing with Mark Kavanagh but was injured.

He was then gelded to try to make him a proper racehorse.

Zephyron was then sent to the Hawkes family partnership, with patriarch John the trainer of champion Octagonal who was out of Diamond Like's grand-dam, the great Eight Carat.

"He was given one more reprieve and Laurie Macri asked if we could take him and see what we could do," Michael Hawkes said.

"He was 25 points out of his grade so it was a great win."

With champion jockey Robert Thompson aboard, Zephyron led all the way in the 1500m benchmark 85 to claim his second win from eight starts with his prizemoney now a fraction of his purchase price at just shy of $64,000.

Macri is a partner in Atlantic Jewel, the top mare which was retired earlier in the week when she was found to be injured after her final workout ahead of Saturday's Cox Plate.

Zephyron's win capped a good day for his breeder Sir Patrick Hogan who is a shareholder in the gelding and also another of Zabeel's progeny, Precedence, winner of the Moonee Valley Gold Cup.

The Bart Cummings-trained eight-year-old is now a chance to line up in the Melbourne Cup for the fourth time if he receives a high enough penalty for winning the race he claimed three years ago.