The end of the road has been reached, some would say mercifully, for the one-time champion racehorse of Hong Kong, Good Ba Ba.

The 11-year-old who arrived in Australia via Macau after his colourful and idiosyncratic owner John Yuen Se-kit decided to end the horse's first retirement after 18 months of inaction, ran his last race behind Black Caviar at Moonee Valley on Friday night.

While bowing out of racing behind the Queen of the turf isn't such a bad way to go, it probably wasn't the best way for such a grand campaigner.

Good Ba Ba, whose name meaning "good father" in Chinese wasn't such an odd one for the many thousands of Hong Kong fans who made him the territory's Horse of the Year, retires as the highest stakes winning thoroughbred in training in Australia.

The catch is that almost every cent of the $A9.3 million he earned from racing was won in Hong Kong.

Good Ba Ba won successive Hong Kong International Miles from 2007 to 2009, the three wins alone earning him the overwhelming bulk of his prize money.

He also won a Champions Mile and was the highest rated horse in the world at that distance.

He had four runs in Australia for Hore-Lacy who insisted until the day of the horse's retirement that he was fit, healthy and sound.

"He's just going to get too much weight in races he's capable of winning," Hore-Lacy said.

"On Friday night at Moonee Valley he looked great, but those sort of races are beyond him now."

The intention had been for Good Ba Ba to run in the Doncaster Mile at Randwick next month.

His next destination is still to be finalised.