Gai Waterhouse and Adrian Bott might have a blossoming Australian Derby contender on their hands after Thinkin' Big made a successful start to his career at Canterbury.

Co-trainer Bott has no hesitation in nominating the Derby next autumn as a potential target for the two-year-old colt after an authoritative debut victory in Wednesday's Spring On Sale Plate (1100m).

"I think he's got plenty of upside. We've sort of pencilled him as hopefully a Derby colt for us going forward and that's certainly a step in the right direction," Bott said.

Thinkin' Big ($7.50) held off a late charge from Rock Zone ($21) to win by a half neck while Irish Songs ($12) was another short head third.

Bred and owned by Peter Dunn who also races the colt's brother, Group Three winner Stampede with Waterhouse and Bott, Thinkin' Big has the pedigree through High Chaparral and Nothin' Leica Cat to suggest he will handle the 2400m of the Derby.

"We had a bit of success with Stampede and Peter thought we might be able to do the same with his brother," Bott said.

"To break his maiden over a distance we thought was well short of his best is very promising and I think the tactical speed he showed today will really help him going forward."

Jockey Blake Shinn was also upbeat about the colt's future.

"Well his name is Thinkin' Big. They're lofty ambitions (the Derby) but he gives you the opinion 2000 and maybe a bit further could be his distance range," he said.