Chris Waller's heart skipped a beat but Nash Rawiller kept his cool to get Red Tracer across the line in Saturday's Millie Fox Stakes after a late surge from Queensland mare Risk Aversion.

Just 40 minutes after Rawiller steered Pierro to a narrow victory in the Hobartville Stakes over Rebel Dane, he was again involved in a tight finish on an odds-on favourite.

Red Tracer ($1.60) gave her all to hold off Risk Aversion ($26) by a half head to defend her title in the Group Three Millie Fox (1300m) and extend her perfect record on heavy tracks to five from five.

"She is a tough little thing," Waller said.

"My heart skipped a beat 10 metres out but she got the job done.

"It was a big effort under 58 kilograms. She is only a small filly. Petite in fact.

"Ideally we'd like to see her ridden a bit quieter so she can attack the line but on a track as wet as today you can't afford to do that."

Rawiller rode Red Tracer hands and heels as the mare has a disliking for the whip.

"It was a very tough effort and when that other horse come at her she was probably entitled to clock off," he said.

"But she found another gear and went again. She's a filly who doesn't like the stick."

The win was Red Tracer's 10th from 24 starts, leaving her less than $25,000 from being a million-dollar earner.

For trainer Michael Lakey, Risk Aversion's effort justified his faith she could be a force in the big Sydney races.

"I knew she liked the sting out of the track but I didn't know if she could handle it this heavy," he said.

"She is down here with a view to going to the Coolmore Classic and I'm pleased with what I saw.

"She hadn't had a trial so she was fresh. At the furlong I started to think she might be able to run into third so what she did is so much better."

Waller had a treble on the day with Catkins and Altered Boy successful in support races on the program.

Altered Boy's return to the winners' circle after a long absence came via a heady ride from Jim Cassidy who took him the shortest route along the fence as others scouted wide.

"What we just saw was Jim Cassidy at his best, and the horse at his best," Waller said.

"It's just a great story because the horse was ready for retirement but the owners wanted to give him one more go."