A fighting victory by Catkins in the feature race at Canterbury capped a stellar day across two states for premier trainer Chris Waller.

Waller dominated Wednesday's Sydney program with four of the seven winners, highlighted by Catkin's performance in the Listed PJ Bell Stakes (1200m).

He also claimed a double at Sandown courtesy of Multilateral and Index Linked.

"It's been a good day and it's good to get a winner in Melbourne at Sandown," Waller said.

"It's hard enough to win when you've got four favourites but I've been fortunate that the horses have been in the right races today, they've all had good rides and good luck."

Catkins jumped smartly from a wide draw and took up the running with Jim Cassidy slackening the tempo once he got to the front.

He rated her perfectly in the lead and she found plenty when challenged by eventual runner-up Diamond Earth in the straight to score a narrow but determined win.

Waller won the corresponding race two years ago with Red Tracer, who will line up in Saturday's Doncaster Mile, and hopes Catkins also has a bright future.

"She might be our next Red Tracer," Waller said.

"I don't think we will be setting our sights too high this preparation but she will come back a nice mare."

Trainer Anthony Cummings was also delighted with the effort of Diamond Earth, a placing he said was significant.

"She did a good job. That is actually her first stakes placing so it counts for a fair bit," he said.

Catkins was the last leg of Waller's winning quartet following the earlier victories by two-year-old Zoustar, Foxbat and Black Jag.