About Square started life as a staying prospect but on Saturday he cemented his future as a sprinter with a victory down the straight course at Flemington.
The gelding's trainer Michael Moroney said the four-year-old had shaped as a stayer when he started his career in New Zealand last year.
"He looked a stayer in the making so we gave him his chance but things didn't go right," Moroney said.
"We finally worked him out, that he was going to be a sprinter."
He said About Square ($8) had a liking for the straight course at Flemington and the stable would attempt to find him another suitable target.
"If we can go on in the spring a little longer it will be great," Moroney said.
The horse was at one stage bound for Hong Kong before Moroney got a syndicate together to keep him in Australia.
About Square held off $1.80 favourite Angels Beach to win the Simone Montgomerie Tribute (1200m) by three-quarters of a length with Lingo ($19) a long neck away third.
The opening races at both Flemington and Randwick were names in honour of the jockey who died after she was thrown from her horse at Monday's Darwin Cup meeting.
TAB Limited has pledged to donate its profits from those races - estimated to be around $30,000 - to the Montgomerie Fund which has been established to assist Montgomerie's family.