The $3.5 million Golden Slipper has been postponed until next weekend as wild weather continues to batter Sydney.
The world-famous race meeting was called off on Saturday after an early-morning track inspection of a water-logged Rosehill racecourse.
Officials said heavy overnight rain and the forecast of more to come made it impossible for the world's richest race for two-year-olds to be run.
Racing NSW chief steward Marc Van Gestel walked the track on Saturday morning before deciding to postpone the day's racing.
Two horses galloped over the course early on Saturday, but further rain confirmed surface water on two sections of the track would have made racing unsafe.
"In the circumstances the track can't cope with any more rain, it's full now," Van Gestel told Sky Sports radio.
"We think in the circumstances we wouldn't be in a position to proceed so we've had to make the unfortunate decision to postpone.
"Given the forecast for today and the way the morning has unfolded we're just not in a position to proceed."
Van Gestel had been confident the showpiece meeting would go ahead after a late Friday inspection despite forecasts of up to 200mm of rain on Saturday.
He was banking on a small break in the weather to provide a window of opportunity to get through the nine-race card before the deluge hit Sydney.
But the meeting's fate was sealed when Rosehill received 25mm of overnight rain, taking the weekly total to almost 120mm.
It marks the first time since the 1963 Golden Slipper won by Pago Pago that the race has been postponed. The race was run on the following Wednesday.
Golden Slipper postponed until next Saturday
The 2021 edition will now be run next Saturday (March 27), while the rest of the Sydney racing carnival will also shuffle back seven days as a result.
Rain is also forecast for Sydney throughout most of next week.
"We certainly have several contingencies in place in terms of how we proceed forward," Van Gestel said.
Golden Slipper day ranks among one of the best race meetings on the Australian turf calendar, with five Group One races decided.
Victorian-trained colt Profiteer held favouritism for the Slipper after a faultless lead-in that included two wins and a close second from three starts.
Besides the Slipper, a highly anticipated clash between outstanding English middle-distance galloper Addeybb and Caulfield Cup winner Verry Elleegant promised to be a highlight.
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