Lightly raced mare Zarzali can't match Angst Stakes favourite Peeping for class or experience but Tim Clark says she has another quality capable of exposing the topweight's biggest vulnerability.

Peeping will step up to 1600m for the first time on Saturday over a Randwick mile renowned for being a tough test of stamina.

If not for the doubt over her at the trip, the Group Two Golden Pendant winner would be much tighter in the market than her current $4 quote.

Clark has no such stamina fears with Zarzali who was stakes placed over a middle-distance as a three-year-old and finished fourth to Winx in the Queensland Oaks.

The James Cummings-trained mare made a stylish return when she came from last on the turn to finish seventh in the Tibbie Stakes at Newcastle and her work since has been sharp.

"She will run a strong mile out and and a few of the others might not," Clark said.

"First-up in the Tibbie she was really good and she's had a trial in between.

"I rode her work on Tuesday and she's going really well. She's forward enough for Saturday for sure."

Supara also brings a Tibbie Stakes formline to the race.

The Gai Waterhouse-trained mare beat just two rivals home at Newcastle but had restricted room for the length of the straight.

She went to the line under a hold to finish just over three lengths from the winner She's Clean.

Tulloch Lodge stable spokesman Mark Newnham said the four-year-old had continued to work well at home and was racing better than her form suggested.

"She's worked well the whole preparation, it's just that a couple of the trips have been too short for her and then she had no luck at Newcastle," Newnham said.

"The mile at Randwick should suit her."

Supara is an $11 chance for the Angst with Zarzali at $15.