Tiarnna Robertson is hoping her winning formula for flying Perth mare Fabergino works again when she lines up for her toughest test in the Black Caviar Lightning.

Robertson has followed the same recipe in the lead up to Fabergino's past two wins by giving the sprinter a month between runs, then taking her to a 1000 metre race at Flemington and letting her use her brilliant speed.

However, her latest assignment will be more difficult.

At Flemington on Saturday, Fabergino will face off against Australia's best sprinters with the likes of Bivouac, Nature Strip, September Run and Pippie among her Group One rivals.

After watching Fabergino work at Mornington on Tuesday, Robertson said her charge was ready for the challenge.

"She's thriving and she's going to have everything in her favour. I can't fault her. She's ticked all the boxes," Robertson said.

Robertson believes that keeping Fabergino fresh suits the mare.

"It's been working well, what we've been doing with her, giving her some down time after racing and then building her up," she said.

"All the time keeping her in work so she's kept her residual fitness."

Saturday will be Fabergino's third run at Group One level but the first time she has had conditions in her favour.

She finished eleventh in the Moir Stakes behind Pippie at The Valley in September but was hampered by a wet track.

Her other Group One start was over 1200 metres in the VRC Classic last spring when she finished last and Robertson said the extra distance was too far for her.

"I'm very excited about her prospects. This time she has things in her favour," she said.

Fabergino has led from the outset in her past two wins at Flemington but that may not be the case on Saturday with Pippie and Nature Strip in the race.

Robertson says she will leave tactics to jockey Jordan Childs.

"I'll leave that to Jordan to work out. We're going into the race confident she's ready to run to her best," Robertson said.

Fabergino has won 11 of her 17 starts and is unbeaten over the Lightning course and distance.