Australia's champion racemare Verry Elleegant has been denied a 12th Group One victory in a shock Golden Slipper day defeat at Rosehill.

Against five rivals in a weight-for-age middle-distance race run on soft ground in which Verry Elleegant has so often excelled, the result didn't go to script for last year's Melbourne Cup winner.

As a $1.24 favourite, the reigning Australian Horse of the Year was expected to make light work of her opposition as she chased consecutive wins in the Ranvet Stakes.

Instead, it was left to another mare to produce one of the biggest upsets of the racing season when Montefilia drew away to leave Verry Elleegant without excuse.

Montefilia ($9.50) was the only runner seriously considered a remote threat to Verry Elleegant.

And despite some stable confidence about her chances, not even trainer David Payne could have envisaged the clear-cut nature of the two-length win.

"First time (this campaign) she should have been much closer to Verry Elleegant," Payne told the Seven Network.

"It's special (to win) because Verry Elleegant is the Horse of the Year."

Verry Elleegant's trainer Chris Waller was daftar pragmatic play in defeat, revealing that jockey James McDonald told him the heavy ground may have been too testing for his stable star over the final 200m.

"I was disappointed," Waller said.

"But full credit to the winner, she is a very good horse in her own right."

Verry Elleegant and Montefilia are set for a rematch in the $4 million Queen Elizabeth Stakes over 2000m at Randwick on April 9.