The Wagga Wagga Gold Cup is the next port of call for quirky mare Gypsy Diamond who has finally lived up to her ability with victory in the Group Three JRA Plate at Randwick.

Senior trainer Peter Snowden said her first win for the stable he runs with his son Paul, had come with some angst.

"I'm bald at the back of my head for scratching it," Snowden said.

"Even today she stood in the gates and missed the start by three lengths.

"It takes a good horse to get past her at trackwork.

"Sometimes with mares they get to the age where you wonder whether they want to be racing or not.

"Her work is brilliant. I work all of my best horses with her. If they stay with her they are going really well.

"She has been promising so much and I've been promising the owners she is going to win and she hasn't been.

"I am glad she did today."

Ridden patiently by Sam Clipperton, Gypsy Diamond ($7.50) came out of the pack to beat Leebaz ($4) by half a length.

"I tried to keep her trotting before the start and that didn't work she still walked out of the gates," Clipperton said.

"But I was able to punch up on the fence. She relaxed quite well mid-race and she wound up through her gears nicely and we hit the line strongly."

Snowden said if she could maintain her winning form, Gypsy Diamond could head to Brisbane for the winter carnival.