Champion trainer David Hayes is confident the best is still ahead of former New Zealand filly Spanish Whisper after the three-year-old raced to her first Australian stakes win at Flemington.

Spanish Whisper won two of her first four starts in New Zealand, including a Group Two race victory as a two-year-old, before joining Hayes' Lindsay Park stable in Victoria after a stable client acquired a controlling interest in the filly.

Hayes, who trains in partnership with his son Ben Hayes and nephew Tom Dabernig, said Spanish Whisper had returned this preparation a better filly than in her first Australian preparation last spring in which her best result was a second in a Listed race.

After finished runner-up in the Typhoon Tracy Stakes in her return from a spell last month, Spanish Whisper ($7.50) lined up in Saturday's Group Two Kewney Stakes (1400m) and chased down stablemate Victory Kingdom to win by a neck.

Western Australian filly Angelic Ruler, the $2.60 favourite, closed late to finish another short half-head away third.

After clinching an Australian Group Two win, Hayes said Spanish Whisper is likely to head to Sydney autumn carnival targets including the Group One Coolmore Legacy Stakes for fillies and mares at Randwick next month.

"I think she's got it all ahead of her because she's just learning how to do things right," Hayes said.

"She's been a bit aggressive and it's taken a while for her to settle in.

"It was a good effort today. She dug in deep and beat what I think is a very good filly."

Jockey Dwayne Dunn believes Spanish Whisper can step up to a higher level.

"She's a top-class filly," Dunn said.

"If she gets the right run in the top-class races she'll be competitive for sure."