James McDonald was ecstatic, Chris Waller apologetic and Catkins simply outstanding in Saturday's Group Three Sheraco Stakes at Rosehill.

The usually reserved McDonald rose in the stirrups as Catkins swept past leader Echo Gal to post a minor upset in the fillies and mares sprint as odds-on favourite Bounding struggled into third.

"She's an absolute privilege to ride. She just doesn't have a care at all. I'd marry this one," McDonald said.

"It felt like a Group One."

Arguably the most popular mare racing in Sydney, Catkins went into the Sheraco with a first-up record of six wins from seven starts.

But Waller feared she might not have been as forward as previous preparations because she was carrying extra condition and she started a $6 chance.

His concerns proved unfounded and post-race Waller was the first to admit he had underestimated Catkins' will to win.

"I might have talked her down a bit which I apologise for but I was only telling what I saw and I saw a bigger horse than normal," he said.

"What I underestimated was her heart. It's bigger than most horse's and takes her a long way."

Waller said Catkins would stay in Sydney for the Group Two Golden Pendant at Rosehill on September 26.

He was unsure of longer-term plans but confirmed the Myer Classic at Flemington, a race she has placed in for the past two seasons, was again on the radar in Catkins' quest for an elusive Group One.

Owner Debbie Kepitis said there were no plans to retire Catkins while she was performing so well on the track.

"She loves racing and we're happy to keep racing her while she is happy to do it," Kepitis said.

"She's got plenty of time to have babies."

Gai Waterhouse was delighted with the effort of Echo Gal and said the plan had been to utilise her speed.

"You can't ride a pretty race on her, her best runs have been when she's very decisive," Waterhouse said.

Bounding appeared to have every chance but couldn't match the first two.