Nigel Blackiston has been rewarded for ignoring the obvious to chase a Group One result with Suavito.

Suavito, first-up since the spring, upset her male rivals to win the $400,000 Futurity Stakes when she could have easily been racing against her own kind in a support race at Caulfield on Saturday.

"I thought why carry 59 (kilograms) in the mares' race and instead have a try at weight-for-age," Blackiston said.

"It was a small field and a perfect race to give it a go."

Suavito's win under Damien Oliver wasn't entirely unexpected because she carried $13 to $10 support before beating Smokin' Joey ($15) by 1-1/4 lengths.

The favourite Dissident ($1.45) was beaten off at the 200m and finished another three-quarters of a length away third.

Blackiston said Suavito was now a valuable broodmare after connections took up an option to buy the daughter of Thorn Park for $65,000.

They originally leased her after she was passed in at the New Zealand yearling sales.

"She's won a Group Three and a Group Two in the spring and now a Group One first-up in the autumn. It's fantastic," Blackiston said.

"We offered to lease her with an option to purchase her for $65,000, which we jumped at."

Blackiston said Suavito would either head to the Blamey Stakes at Flemington or the Coolmore Classic at Rosehill on March 14 for her next start.

Oliver said he was surprised by the win after watching Suavito barrier trial at Flemington.

"She didn't trial like a Group One horse but it just shows she brings out her best on raceday," Oliver said.

"She flies here and first-up. She put herself in a good position and she was able to capitalise on it."

Ben Melham, who rode the heavily backed Dissident, said the entire ran below par.

"There wasn't a lot of tempo and I would have liked him to relax a bit more, but overall he's had an off day," Melham said.

"He didn't race like his usual self."