The daughter of Azamour has a liking for rain-affected ground and handled the rise in distance from 1400m fresh-up to 2000m with aplomb, scoring a comfortable win under James McDonald.
Prepared by Chris Waller for her New Zealand owners, the champion trainer joked that a pep-talk from a star stablemate may have worked the oracle in seeing Polly Grey return to the winner's circle.
"We just put her next to Verry Elleegant for one night, that was all," Waller quipped.
"She's a decent horse and obviously she is superior on these types of tracks and this distance as well.
"She is pretty fit. She had a trial between the 1400 metre race and today.
"The trial is a fill-in type race, a bit less stress but they're still doing the work, so I think that's a big help."
The well-supported mare cruised through the testing ground to outstay stablemate Mightybeel ($3.80 fav) by 1-1/4 lengths with Grove Ferry another neck away third.
The winner is likely to be aimed at the Gr.3 Summer Cup (2000m) at Randwick on Boxing Day before returning for some of the second-tier middle-distance races during the autumn.
Waller said Sydney's healthy prizemoney levels not only made ownership attractive, it also encouraged connections to keep horses racing longer, pointing to Polly Grey as a perfect example.
The top trainer has no doubt Polly Grey would have been retired at the end of last autumn if not for the significant stakes on offer and the winner of ten races has now advanced her record to 10 wins and prizemoney of A$631,929.
"I think that would be a good example of prizemoney and how it keeps horses racing longer because she would have gone to the breeding barn for sure," he said.
Waller was also satisfied with the effort of Mightybeel, who sports the colours of Go Racing and ran on well but was no match for the winner at what was his first test at black-type level.
"I thought he went pretty good. He can actually drop back a grade to a benchmark 88 in three weeks' time and that is probably where he will go," Waller said.
Polly Grey joined Waller in the middle of 2020 after winning six races for Matamata trainer Kylie Fawcett, including the Listed Matamata Cup (1600m).
Fawcett races Polly Grey with her partner Rob Joyce and brother Brook, while she leased a half-share in the mare to Auckland client John Thompson, and she races in his colours.
Bred by the late Barbara Perry, Polly Grey was bequeathed to Fawcett, who looked after Perry's small broodmare band and young stock at her Oxford Thoroughbreds, 10 kilometres south of Matamata.
Polly Grey is by ill-fated shuttle sire Azamour, who spent just the one season at Brighthill Farm in 2013 before his untimely death at Gilltown Stud in Ireland in 2014.She is out of the four-time winning Zenno Rob Roy mare Allanah, a half-sister to Group One winner Pasta Post and Group Three winner Don Domingo.