Captain Duffy has earned himself a shot at the Victoria Derby with a strong staying performance at Geelong.

The South Australian-trained three-year-old, who has been based at Caulfield for the spring, outstayed his rivals to take out the Geelong Classic on Wednesday.

A pick-up ride for Noel Callow following Craig Williams' failed appeal against suspension on Tuesday, Captain Duffy ($21) scored by 1-1/4 lengths from Hollywood Mo ($19) with Pretty Punk ($4.40) a half-head away third.

The three-year-old's Derby price was slashed from $101 to $13 following his on-pace victory.

Captain Duffy was having his fourth start in Melbourne this campaign and was one of six horses trainer Phillip Stokes' sent to Melbourne for the spring.

The colt gave owners Ultra Racing a well-timed victory ahead of the Victoria Derby on October 29.

Toby Koenig, general manager of Ultra Racing and the organisation's vet, said Captain Duffy was on his last chance as a possible Derby contender.

"We needed to see a good performance today to press on to the Derby otherwise we were going to look to easier options in South Australia," Koenig said.

Koenig says Captain Duffy is by a sire that should command more attention than he receives.

"King Cugat only gets about 10 mares a year but he always gets a winner," Koenig said.

"He probably deserves a few more than he gets.

"This guy is a lovely big horse and has always shown he wants to stay.

"It was always the plan to go forward today as he jumped so well at Flemington two weeks ago and we knew he had a fair bit going for him.

"Noel's got the pick-up today and did a terrific job."