James Cummings was destined to become a racehorse trainer.

Whether he expected to be heading Sheikh Mohammed's Australian Godolphin operation and holding a Golden Slipper at the age of 31 is another thing altogether.

His father Anthony is a multiple Group One-winning trainer, his grandfather Bart won more Melbourne Cups than anyone else and his great grandfather Jim started it all with Comic Court in the 1950 Melbourne Cup.

On Saturday at Rosehill, Anthony Cummings was the proudest father on course after Kiamichi beat stablemate Microphone in the $3.5 million Slipper for two-year-olds.

He said of his four children, James was always the keenest when it came to the horses.

"He's just done a fantastic job," Cummings said.

"It's just been a fantastic result I think from both sides. He's got the best out of the horses and that's a trainer's job

"He was the first one to put his hand up and was the most interested.

"All the children had an exposure to the horses and worked in the stable.

"They all had time away overseas doing different things and James was the one who picked it up and ran with it first.

"It's just great to see. It's a very, very special day."