Trainer Danny O'Brien has his sights set on a Group One race with three-year-old filly Toffee Nose after her victory against older horses at Caulfield.

Toffee Nose raced to a comprehensive victory in the VOBIS Gold Heath (2000m) on Saturday with O'Brien now eyeing the Australasian Oaks at Morphettville on May 6.

O'Brien explained the Group One race in Adelaide was his aim after Toffee Nose finished fourth in the Wakeful Stakes at Flemington last spring.

"She ran very well in the Wakeful but it was her first racing prep and we thought it was a bit much to go to the (Victoria) Oaks," O'Brien said.

"We put her away with Adelaide in mind and this race fitted in nicely.

"Going to the 2000 metres today will have her spot on for two weeks time."

Ridden by Damian Lane, Toffee Nose ($5) scored by a length from the $2.80 favourite Ruthven with Tarquin ($11) 1-1/4 lengths away third.

O'Brien said he had trained Toffee Nose from his beach property at Barwon Heads this campaign and is looking forward to testing the filly over 2400m.

He hasn't ruled out sending the filly to Brisbane for the Queensland Oaks in June.

"She's out of a Galileo mare so there's a huge chance she'll run 2400 metres," O'Brien said.

"If she won or ran well in Adelaide then we're more likely to go to the Group One with her in Queensland."