Damien Oliver is one of only seven jockeys to have captured the four big races of the Australian calendar.
His bag includes two Cox Plates, three Melbourne Cups and four Caulfield Cups.
Success aboard Seabrook in Saturday's Golden Slipper Stakes at Rosehill would give him a second victory after Forensics won in 2007 and make him the first rider to win a double grand slam.
Oliver was shattered Seabrook didn't make the final cut for last month's Blue Diamond Stakes but believes the filly can make up for that disappointment on Saturday.
Seabrook sits on the third line of betting for the Golden Slipper at $8.50 behind Sunline ($4.20) and Written By ($5).
After being promoted to third following a successful protest in a Prelude a fortnight before the Blue Diamond, Seabrook didn't have the required prize money to make the final field.
To secure her berth in the Golden Slipper, Seabrook was sent to Sydney where she won the Sweet Embrace Stakes at Randwick on March 3 under Hugh Bowman.
Oliver was required for rides in Melbourne that day, winning the Australian Guineas on her Mick Price-trained stablemate Grunt, but kept a watch on the filly.
"She's come up really well this preparation and I think she probably should be unbeaten as she got knocked over in the Prelude," Oliver said.
"She's a really nice filly and we don't know about the wet obviously, but then there's a lot in that basket also I suppose."
Oliver pointed to the form from her placing in the Prelude as a guide to her chances on Saturday.
Enbihaar won the fillies Prelude before running second to Written By in the Blue Diamond two weeks later.
"It was disappointing she didn't get into the Blue Diamond," Oliver said.
"I'm sure she would have been really competitive in the Diamond but it would be good if we could get a nice consolation win in the Slipper."