Tommy Berry has made the most of what may be a one-off opportunity to put More Joyous through her paces in a barrier trial at Randwick.
Her regular race partner Nash Rawiller is recovering from a broken ankle so
Berry got the chance to steer the pin-up mare in the 1050m trial which she won without being pushed.
The Gai Waterhouse-trained multiple Group One winner is the second favourite to defend her Doncaster title behind All Too Hard and her younger stablemate Pierro.
Berry, the stable's number two ride behind Rawiller, said she did everything he asked.
"It was an absolute pleasure to ride her today," Berry told Sky Sports Radio.
"I've ridden Group One winners now but she gives you a different feel. She gives you goose bumps.
"She's such a beautiful horse to ride.
"We weren't out there to break any records and she was pretty much under a hold the whole way."
More Joyous edged past Ashokan to win her heat by a half head in 1:03.20s.
Berry is much better acquainted with Metropolitan winner Glencadam Gold and rode him to a three-length win over stablemate Julienas in a 1200m heat.
"He was pretty impressive and it's amazing how well his fitness has come along from his first to his second trial," he said,
"He put them away pretty quickly."
Glencadam Gold is on the third line of betting for the Australian Cup behind Melbourne Cup winner Green Moon and All Too Hard.
Among the other horses Berry rode for Waterhouse on Friday was Breeders' Plate winner Whittington who is headed to the Golden Slipper.