On a day he had hoped to be in Melbourne, Tommy Berry drew first blood at Randwick with two-year-old Sweet Idea for his boss Gai Waterhouse.

In an ironic twist, Sweet Idea sported the same colours Descarado wore to give Waterhouse her first Caulfield Cup two years ago.

Berry made the best of the finish on the $5 chance to beat Trent's Quest ($10) and $2.20 favourite Citations to take out the first race of the day at Randwick, the TAB Sprint Plate (1000m).

The young Sydney jockey was dumped from this year's Caulfield Cup favourite Glencadam Gold in favour of Jim Cassidy, despite proving his mettle on the horse in the Group One Metropolitan.

A diplomatic Berry said he was keeping focus on the job before him at Randwick.

"I try not to think too much about that, I just worry about me today," Berry told AAP.

The win has set the scene for Sweet Idea to head to the $2 million Magic Millions at the Gold Coast in January.

"Hopefully we'll aim her towards there," Waterhouse stable representative Mark Newnham said.

"Gai might decide to give her a little break now, that should help qualify her there."