Young gun Jason Collett had a win in the stewards' room on Saturday and will be looking to celebrate with an even bigger victory a week later.

Collett rides She's Clean in Saturday's Tatt's Tiara for fillies and mares, one of two runners for Chris Waller in the final Group One race of the season.

The jockey appeared to be staring suspension in the face but was successful in having a careless riding charge downgraded at Rosehill, incurring a reprimand.

That has him in a jubilant mood as he heads to the Tatt's Tiara (1400m) at Eagle Farm with She's Clean, a last-start winner of the Listed June Stakes at Randwick.

Although Red Tracer, who will be ridden by Nash Rawiller, is by far the more experienced of the two Waller-trained runners, Collett doesn't think there's too much between them.

"They are two similar fillies," Collett said.

"They both just try so hard and I'm looking forward to the Group One.

"I'm also riding Thumbtacks for Chris in the Tatt's Mile."

The winner of eight of her 16 starts, She's Clean has only raced twice at stakes level for a perfect record.

And her win in the Triscay Stakes in February could prove to be a defining one.

She beat Appearance by a short half head with the Guy Walter-trained mare going on to win Sydney's two Group One fillies and mares races - the Coolmore Classic and Queen of the Turf - with Red Tracer second on both occasions.

Last season's champion New Zealand apprentice, Collett has now settled in Sydney after previous winter stints with Waller.

In his first season as a senior rider he has made his way into Sydney's top 10, currently sharing ninth place with Jim Cassidy who is now on his annual break.

Cassidy has ended his season on 98 Group One wins while Collett is still waiting for his first.

It would be fitting if it came for his mentor Waller who is the leading Group One trainer in Australia this season with nine.