Adelaide trainer Will Clarken has achieved a milestone first Group One win with bargain-buy Bella Vella who has capped a stunning rise in the Robert Sangster Stakes at Morphettville.

Bella Vella was bought online for $22,500 last year and she has won six of her 11 starts since joining Clarken's stable last year, with Saturday's Group One clearly the highlight.

Giving jockey Todd Pannell his second career Group One win after last year's Goodwood on Despatch, the speedy Bella Vella stretched out to 1200m and held off a late charge by last year's Blue Diamond Stakes winner Lyre to score by a half-neck.

The Ciaron Maher and David Eustace-trained Bam's On Fire was another 1-3/4-lengths away third while her stablemate, two-year-old filly Away Game finished fifth in her bid for an historic win in the race against the older fillies and mares.

"David Jolly actually found her and some of my owners were looking at her as well so we put a syndicate together and bought her," Clarken said.

"Obviously it's a fairytale story now."

Bella Vella had previously been sent to the breeding barn but did not get in foal to Criterion and was later offered for sale online and snapped up by her new connections.

Clarken said his first Group One win was "very, very special" especially with some friends and long-time supporters in the ownership and with Pannell aboard.

"I've had lots of runners in Group Ones and I suppose you've just got to keep rolling the marble," he said.

"Today she got left alone in front.

"She's been in super form and things went our way."

Bella Vella's overall record now sits at nine wins from 28 starts and Clarken said she would not press on to The Goodwood in two weeks but would be given a break with a view to the Group One Moir Stakes (1000m) at The Valley in spring.

Two of Bella Vella's wins for Clarken have been in 955m sprints at The Valley.

"We're just happy to get the win today," Clarken said.

"Everything she had in her she gave to us. And I think she deserves the time now."

Three-time Group One winner Sunlight started $3.20 favourite and raced on the pace but faded to finish last.