Over the past 30 years, Jim Cassidy has ridden many of the champions of the Australian turf but none as good as Pierro.

Cassidy labelled the colt the best he had ever ridden after the three-year-old beat glamour mare More Joyous to win the Canterbury Stakes (1300m) on Saturday.

It was the veteran jockey's second Group One victory on the Rosehill program and came little more than an hour after Foreteller took out the Ranvet Stakes.

Pierro was sent out the $2 favourite to extend his unbeaten record in Sydney to nine in what had been billed as a match-race with his Gai Waterhouse-trained stablemate More Joyous who had won twice when it was at Group Two level.

As expected, Rain Affair set out in front with Pierro parked third and More Joyous midfield.

Cassidy made his move on Pierro in the straight and he dashed clear with More Joyous gaining ground late to finish within three-quarters of a length.

"He is the best horse I've ever ridden," Cassidy said.

"He is an absolute freak.

"Might And Power was a champion but you had to switch him off and on. This horse is just so easy to ride."

Cassidy was only riding Pierro because Nash Rawiller was committed to More Joyous who he said had given her all.

"She was in a bit of an awkward spot early but I thought she was pulling ground off him late," Rawiller said.

"I think perhaps the blinkers should go back on if she is going to run over 1500 metres in the Queen of the Turf."

John Singleton, owner of More Joyous, said the mare's plans hinged on whether the promise of a $1 million prizemoney boost for the All Aged Stakes materialised.

There has been a push over the past couple of weeks to attract a star-studded field including Black Caviar to the 1400m race on April 27 with a corporate bookmaker saying it would help with the funds.

"We'll see what happens with the All Aged," Singleton said.

"She ran well but it's still a bit of an empty feeling."

Queenslander Solzhenitsyn ran third in what trainer Rob Heathcote described as an ideal lead-up to his assignments in the George Ryder Stakes and the Doncaster where he is likely to run into Pierro again.