James Cummings will saddle up his first Group One runner as a trainer in his own right when Ocean Tempest takes her place in Saturday's Flight Stakes at Randwick.

A defining moment in the career of any trainer, Cummings admits the milestone almost slipped past without notice.

Not because of a lack of significance but perhaps as a result of the seamless transition Leilani Lodge has made since the death in August of Cummings's grandfather, mentor and training partner Bart.

James Cummings worked alongside the man regarded as Australia's greatest trainer for half a decade, first as foreman and later as co-captain.

In that time he saddled up top horses in big races including So You Think, Norzita, Hallowed Crown, Faint Perfume and Eurozone.

Bart Cummings defied an allergy to horses to spend his life around them and with the same no-nonsense attitude, his grandson has put aside his own grief and immersed himself in continuing the legacy of Leilani Lodge.

"To have my first runner in my own name in a Group One is a milestone that takes me by surprise because it's business as usual," Cummings said.

"When I first saddled up horses like So You Think, the pressure was on and I felt the pressure as a foreman as if I was completely responsible for the horse's performance because that was the way I was taught.

"I think that's stood me in good stead."

"These races are what my owners are in racing for. It's what the stable is working really hard towards."

Ocean Tempest was also paid up for the Dulcify Quality but with just one Flight Stakes rival proven at the 1600m journey, Cummings sensed an opportunity for his filly.

Norzita won the 2012 Flight Stakes at her first racing campaign, the same challenge Ocean Tempest faces.

And for Cummings, a glance at the race's honour roll confirmed his thinking.

"Flight Stakes aren't won by horses that are just sprinters," he said.

"They're won by horses that in 12 and 18 months time are genuine open-class Group One milers.

"I suspect my horse has the potential to get to that sort of level."

A half-sister to Cummings's promising stayer Ruling Dynasty, Ocean Tempest has the right bloodlines.

A bit like her trainer.