After a winning treble from as many runners on Caulfield Cup day, the Gai Waterhouse and Adrian Bott stable has started Cox Plate day on a bright note with Setsuna.

Two-year-old filly Setsuna finished a close second on debut in the Listed Gimcrack Stakes at Randwick on September 30 before attention turned to Saturday's $250,000 Inglis Banner at Moonee Valley.

Despite not beginning as quickly as expected in the 1000m race for juveniles, $4 favourite Setsuna sat three-wide with cover before chasing down eventual runner-up Bionics ($9) to win by three-quarters of a length.

Grand Challenge ($8.50) ran on from back in the field to finish the same margin away in third.

Setsuna races in the colours of syndicator Darby Racing who have enjoyed plenty of success in recent seasons with Group One juvenile winners Yankee Rose and She Will Reign.

"Scott Darby said to Adrian when he gave us the filly to train, he said 'here's your Gimcrack Stakes filly'," Waterhouse said.

"She was only quite small and diminutive but she was only beaten a nostril in the Gimcrack. So after that we said she's going to Melbourne for the Inglis Banner."

Waterhouse believes the filly has a bright future and will discuss options with connections.

Jockey Stephen Baster was anticipating Setsuna would begin quickly and allow him to cross to the lead but instead had to go to plan B.

"She half bunny hopped out of the gates and put her in an awkward spot," Baster said.

"I thought I was going to be four wide without cover but 100 metres later I was three deep with cover and had a lovely run. She was a bit green but that race experience helped."