"He's getting better each time and I think he's definitely going to be a 2000 metre horse," Breslin said.
Stephenstihls settled back in the field and once rider Johnathan Parkes eased him away from the fence across the top the son of Smart Missile moved ominously into contention.
"He was a bit tardily away, but I was able to get out at the 600 and get him rolling and he finished off well," he said.
"He's still got a bit more maturing to do and once he gets over a bit more ground I think he'll be a pretty good horse."
Stephenstihls held off the late challenge of McPhoebe, who charged home from the tail end of the field, by a head with the maiden Bring To The Block an eye-catching third.
The favourite and the winner's stablemate Sweepstake, who was making her first appearance since finishing third in the group one NZ 1000 Guineas, never threatened and finished seventh. She settled off the pace and couldn't make any impression in the run home.
"She got into a bad spot and I'm not too worried," Breslin said. "She'll run in the Desert Gold Stakes as long as she pulls up well."