On day one of The Championships at Randwick, Tyler Schiller’s leading Group One prospect is Briasa, the T J Smith Stakes reigning victor, although he maintains his other selections are undervalued.

The proficient rider further saddles Paul Preusker’s Steparty ($19) for the Doncaster Mile (1600m) alongside Dezignation ($151), under Matt Smith’s care, in the ATC Australian Derby (2400m), rating them as viable upsets.

Dubbed the field’s outsider for the Derby, Dezignation powered home late for fifth versus upcoming opponent Storm Leopard ($5) in the Tulloch Stakes (2000m), and holds an edge with established endurance at the distance against numerous rivals.

Schiller debuted on the gelding in the recent lead-up and was notably taken by the display.

“He sneaks in off a really good run in the Tulloch,” Schiller said.

“He got back and was taken off the bridle a long way from home, and he stayed on super strong. He just needed a bit further, which he is going to get this weekend.

“As long as he backs up, he’s going to have a really good chance, and he’s got a lovely barrier compared to his outside barrier the other day.

“If it’s a good staying test, he is going to be in the finish.”

Steparty, meanwhile, flies low in Doncaster Mile considerations dominated by elite filly Sheza Alibi.

This five-year-old with various Group 1 berths has appeared in Sydney outings previously, like his near-win in the 2024 The Ingham (1600m) over the Doncaster course.

Coming off February doubles in Tasmania, Steparty prepares for the feature post a tight fifth to Tom Kitten in the All-Star Mile (1600m) at Flemington, with barrier six promising a straightforward passage.

“He’s a really nice horse. He’s got a great attitude and he’s another one flying under the radar,” Schiller said.

“He got beaten a length and a bit in the All-Star Mile off a tough, wide run, and he’s going as good as ever.

“Fingers crossed, barrier six is a lovely barrier in the Doncaster. Hopefully he can bounce and get a bit of cover somewhere and save himself for late. He drops a lot in weight, so I think he might surprise a few people.”

Steparty has handled 59kg in each of his prior three weight-for-age races, lightened to 51.5kg at Randwick.

First Derby glory and another Doncaster Mile await Schiller, building on Celestial Legend’s victory from two years past.

Look at betting markets for the race ahead of the ATC Australian Derby.