A yearling sales gamble has turned into a genuine autumn carnival chance for freshman Sydney trainer Sam Kavanagh after Interspersed won the Canberra Guineas on Sunday.

"It was ridiculous to go the sales without a client and spend $140,000 for a horse but I was keen on (her sire) Sebring. I knew the family and I knew she had some value if she didn't make it to the races," Kavanagh said.

"It was a calculated guess."

But sometimes buying a horse is the easy part and Kavanagh admitted he found it hard to market the filly to potential clients.

"She was really hard to sell so it's just nice to get this result," he said.

Interspersed ($7) entered an autumn carnival picture for three-year-old fillies with a brilliant burst from the back to beat Lorna May ($5.50) in a close finish to the 1400m Listed race.

Jason Collett let Interspersed find her rhythm at the back of the field before producing the filly down the centre of the track to score by a half head.

Liberty's Choice ($5), who ensured it was a genuinely run Guineas, held down the minor placing after looking set for victory at the 200m.

Kavanagh is the son of leading Melbourne trainer Mark Kavanagh and he set up Rosehill stables last year after moving from Adelaide.

Midsummer Sun gave him a breakthrough NSW stakes win in the Gosford Gold Cup in January but he is certain Interspersed can achieve greater heights in coming weeks.

She is on an ATC Oaks path and will head towards the $1 million race via the Keith Nolan Classic at Kembla Grange and the Group One Vinery Stud Stakes.