Hayasugi proved herself Melbourne’s best two-year-old with a stylish win in the Blue Diamond Stakes completing a rare treble in the process.

The Clinton Mcdonald -trained daughter of Royal Meeting joined Midnight Fever, back in 1987, as the only filly to complete the Blue Diamond Series, comprising the Preview, Prelude and Saturday’s feature Group 1 race over 1200m.

Three colts, Rancher (1982), Bel Esprit (2002) and Sepoy (2011) had also completed the feat.

Ridden by Jamie Kah, Hayasugi ($16) defeated Lady Of Camelot ($4.40) by a long head with Kuroyanagi ($11) a head away third.

The Group 1 Golden Slipper (1200m) at Rosehill on March 23 beckons for Hayasugi who will try to emulate the deeds of Courtza who won the Blue Diamond-Golden Slipper double for McDonald’s father Ross.

“It’s one of those races where I used to say to my mates, history repeats,” McDonald said.

“Blue Diamond, Golden Slipper and we’re lucky enough now to have a live chance and I think the Golden Slipper will really suit this filly and the way she attacks the line.

“For a young two-year-old, her tenacity is second to none.

“She’ll go straight to the Slipper. I’m sort of following the same program we did with Courtza and that’s what she’ll do.”

McDonald said a win in a feature race like the Blue Diamond was important for the stable.

He said it shows future owners that he can train a young horse to win Group 1’s.

“We’re only a small stable and we always seem to have a good horse in the stable but today, I’d never been so confident coming to the races with a horse,” McDonald said.

“It was a faultless preparation, she looked magnificent, and it was just unreal.”

Kah landed her first win in the Group 1 feature and was congratulated by fiancée Ben Melham soon after returning to the jockeys’ room.

The couple became engaged on Valentine’s Day.

“It’s been fantastic. Almost as good as my ring,” she said.

Kah rode Hayasugi to all three wins in the Blue Diamond Series after Melham partnered the filly at her second race start last spring.

She said Hayasugi is a determined filly who does not know when she is beaten.

“She gives you a nice enough feel on the turn, and she just finds ten lengths,” Kah said.

“I don’t know how. Today she gave me a nice feel, I thought she’d run on well, and she wins, she’s just so tough. So tough.

“The team’s done an amazing job with her but the horse itself, she’s just coped with everything.

“She was the quietest horse out there, she was a pony. She just loves her job, loves her work.”