Trainer Bjorn Baker has taken three horses to the races at Rosehill and come away with his first metropolitan treble.

Test The World got the ball rolling on Saturday and was followed by Sir Plush and Collateral.

Any doubts Baker had about the wet track first-up with Sir Plush were erased with his win in the Schweppes Handicap (1100m).

"I thought he'd come back really well though I was very concerned about the track," Baker said.

"He's got good gate speed and it was a super ride by Jason (Collett). He summed it up."

Sir Plush ($4.80) beat favourite Badajoz ($4.20) by 2-3/4 lengths.

Collett was also aboard Test The World and Baker had a query about her ability on the wet track in the ATC Membership (1200m).

But the filly dispelled those fears to lead all the way to win in a photo-finish.

"I did have a question mark over her on the wet ground but she handled it and I've got a lot of time for her," Baker said.

Collateral is a relatively new addition to the Baker stable and has posted two third and three wins from his five starts for the trainer.

He went from midfield to win the #theraces Handicap (1800m) by a long neck from $2 favourite Carzoff.

"I've only had him this prep," Baker said.

"He's an exciting horse.

"And it's exciting to get a treble. It's my first on any metropolitan track, not just a Saturday.

"And to do it with three runners is satisfying."