A decision on Streama's racing future is expected this week but her trainer Guy Walter believes her Doomben Cup win is an ideal way to end her career.
The five-year-old added Saturday's Group One feature in Brisbane to her Group One wins in the Flight Stakes, Australian Oaks and the George Main Stakes.
Walter said the final call would come from her owners, the Coghlan family who bred Streama who is by 2005 Golden Slipper winner out of Sovereign Red mare Pensiamo.
"I don't want to pre-empt the owners but I think the Doomben Cup is an ideal way for her to go out," Walter said.
"I'd like yesterday to be her final run and I've expressed that to the owners.
"They will make a decision in the next few days.
"She can't get any better and can only start to lose a length or so.
"I don't think she can do any more.
"She started as an autumn two-year-old and here she is winning a Group One as a rising six-year-old.
"They don't come much better than her and it's been a privilege to train her.
"She has won over all distances and has never had an unsound day in her life."
As well as Streama's George Main Stakes and Doomben Cup, Walter claimed a third Group One this season with Appearance, another five-year-old mare who was retired with four victories at the highest level.
The Darley-owned mare was retired due to injury in the autumn, going out a Group One winner of the Canterbury Stakes.
Streama's record stands at 10 wins and 13 placings from 34 starts and she has earned more than $2.6 million.
Her Group One performances include five minor placings.