I Am A Star won 10 of her 31 starts, including the 2016 Group One Myer Classic at Flemington.
Tahitian Dancer made the retirement decision easier to swallow when successful in Saturday's Cleanaway Handicap before Streets Of Avalon made the day sweeter collecting the Listed Hareeba Stakes at Mornington.
Streets Of Avalon was backing up from finishing third in a Listed race over 1400m at Flemington last Saturday.
“He's an amazing horse,” Nichols said.
“To bring him back from 1400 metres in seven days to win at 1200 metres, the staff need to be congratulated.
“He's had a long prep and it doesn't happen easily so to win the Hareeba, on the home track, I'm really chuffed about that.”
Streets Of Avalon is now the winner of five races from his 30 starts and more than $500,000 in prize money.
“A year ago if you had told me that he'd be a 96-rater and winning at stakes level, I would have said no,” Nichols said.
“There might be a bit more to come, but it depends on where his rating goes to after this.
“There's a Listed race in two weeks at Caulfield over 1400 metres, so we'll go there and see how it unfolds.”