Worthy Cause handled his first middle-distance attempt with ease in Saturday's Gunsynd Classic but trainer John Zielke is unlikely to aim him at the Queensland Derby.

Ridden by Justin Stanley, Worthy Cause surged clear in the final 100m to win by two lengths from Upham ($17) with Chillin With Dylan ($31) 1-1/4 lengths away third.

Zielke has his sights firmly set on the spring carnival in Melbourne for Worthy Cause and is reluctant to pursue a Queensland Derby campaign with the colt.

"This horse will run 2000 metres and beyond in time but my goals during the winter carnival are to keep him at the mile in the Sunshine Coast Guineas before the Queensland Guineas," Zielke said.

"After that I want to give a short blow then have him ready for the spring carnival in Melbourne."

Worthy Cause, backed from $5.50 into $4 equal favouritism, was stepping up to 1800m after winning over 1350m at Doomben a week ago.

"Some people I thought I was crazy backing him up in the space of a week and stepping up from 1350 metres," Zielke said.

"I've done it before with Kengrande when he won at Flemington during Cup week a few years ago and I know what's required."

Worthy Cause was Stanley's first win at black-type level since 2013.

Stanley was confident Worthy Cause would win when he was travelling comfortably.

"He usually hits a flat spot just before the turn, and today was no exception, but in the straight he's got a great turn of foot," Stanley said.