Jockey Michelle Payne will miss her debut at Royal Ascot next month after abdomen surgery following a fall.
She is described as being in a "serious but stable" condition, is heavily sedated and will remain in hospital in Australia for at least a week, but is expected to make a full recovery.
Payne made history in 2015 by becoming the first female rider to win the Melbourne Cup, on Prince Of Penzance.
The 30-year-old said she was in "acute pain" after falling from Dutch Courage.
She is not expected to ride for the remainder of her domestic 2015-16 season, which finishes on 31 July.
Payne told the BBC earlier this month she was relishing a trip to Europe, including Royal Ascot, but is also now a doubt for the Shergar Cup at the Berkshire track in August.
Victorian Jockeys' Association chief executive Des O'Keefe said: "Surgery has been successful and Michelle will be remaining in hospital for at least a week, perhaps more. She's in a serious but stable condition."
O'Keefe added: "She's very very lucky. Any fall from a horse, particularly at 60km an hour is a tricky outcome
"It looked reasonably innocuous at the time and it's ended up significantly more serious than that, but hopefully the recovery will be full and complete.
"I'm sure she'll have mixed feelings - happy that it could have been a lot worse but also bitterly disappointed given the amount of work she's been doing and some overseas engagements that will now be on hold."