A grandson of Octagonal has won a stakes race at Caulfield on the day the former Australian Horse of the Year died.

Peacock, a son of Octagonal's best son Lonhro, won the Listed Gothic Stakes on Saturday for Godolphin.

Octagonal was euthanised at Woodlands Stud on Saturday following ill health.

Godolphin trainer John O'Shea said it was a sad day for the those involved with Woodlands Stud.

"He was a great racehorse and an iconic horse in Australia," O'Shea said.

"He was well looked after and he's got his place in Australian racing."

Ridden by Dwayne Dunn, Peacock ($19) scored by a short half-head from Violate ($19) with the $2.60 favourite Acatour a half-length away third.

The Godolphin team saddled up three runners in the race with Morton's Fork (fifth) and Trenchant (seventh).

"We came here thinking Peacock would be very hard to beat because he would get the gun run and that's the way it played out," O'Shea said.

"The other two acquitted themselves well and going to Flemington we are optimistic they can ran well there too."

O'Shea said Morton's Fork and Trenchant are pencilled in to contest the Carbine Club Stakes at Flemington on Derby day while Peacock will be saved for the Hilton Stakes over 1400m on the final day of the four-day Melbourne Cup carnival.

"I think 1400 metres is at the upper reaches of his distance range," O'Shea said.

The victory was Godolphin's 16th stakes win of the season, continuing a run of landing at least one black-type race win on nine consecutive Saturdays.