He rang Harvey's racing manager Claire Bird with his concerns about running and got a return call with the advice from Harvey.
"Gerry said, 'Don't give up so easy. You set her for the race in November. Work her in the morning and see what you think'. She worked that well on Tuesday morning so we thought we'd give it a go."
Mrs Onassis ($16) sat outside the leader Adebisi during the run before hitting the front at the 200m mark.
The 5-year-old powered to the post to win by a length, holding off the Queensland challenge with Facile Tigre ($15) second and Spirit Of Boom ($11) another three-quarters of a length away third.
It was Mrs Onassis' seventh win from 12 starts at 1100m.
"She's just getting better as she gets older," Ryan said. "After she won here in the spring, Gerry said to aim at the Oakleigh Plate."
The group one Galaxy in Sydney, also over 1100m, is the next target.
The victory also gave Kerrin McEvoy a group one win on a day he expected to play a role in the Blue Diamond Stakes, only for Guelph to finish out of the placings.
Jason McLachlan was delighted with the performance of Facile Tigre.
But he must be wondering what it's going to take to win the Oakleigh Plate after the gelding was beaten into third in a close finish last year.
- AAP