The Wendy Roche-trained mare was a $20,000 buy at the Inglis Ready To Run sale and is expected to fetch much, much more as a broodmare prospect at the Chairman's sale in May.
The five-year-old had won two races before Saturday's 1600m-event for fillies and mares and had been placed five times at stakes level including last year's Aspiration.
The mare is a little highly strung and her trainer had to travel in the truck with her from Warwick Farm.
“She got her out of her box so I had to change my dress and shirt, hop in the back of the float with her,” Roche said.
Nettoyer ($4.80) made a sustained run from worse than midfield and surged to the line 1-1/2 lengths ahead of Luvaluva ($8) who nabbed second by a head from Luskintyre Lass ($4.60 fav).
Roche did not underplay the importance of the win.
“I had to throw her in the deep end as she broke her pelvis early on so just in case she didn't come back we wanted black type,” she said.
“Although everyone said we threw her in, there was a reason.”
In his previous three Group One wins, Trapeze Artist was ridden by Tye Angland who was this week confirmed quadriplegic after a fall in Hong Kong in November.
Angland was on course on Saturday with jockeys dedicating their rides in the Canterbury Stakes to him.
While pleased with all three wins for different reasons, Shinn was thrilled for Roche.
“This is all about Wendy,” he said.
“This is her headline horse. It's great for Wendy to win a Group Three on a big day here at Randwick. It's really special for her.
“The mare is top class. It's just a matter of finding her niche in terms of the right distance range and everything panned out nicely today.”
Victorian mare Hiyaam claimed her first win since the Group One Vinery Stud Stakes in March last year when she took out the Listed Randwick City Stakes.
Trained by Mick Price and ridden by Tim Clark, Hiyaam led all the way to hold off Shraaoh by a short neck.
She holds entries to the Group One Queen Elizabeth Stakes and Sydney Cup.