Former New Zealand galloper Start Wondering has made an immediate impression on trainer Chris Waller, defying a wide run to win on debut for the stable.

Starting from an outside gate, the five-year-old travelled three-wide for most of the race before accelerating clear to beat His Majesty and Radical Impact in the ClubsNSW Hcp (1350m) at Rosehill on Saturday.

Waller described the win as special and said the horse's ability to cope with a wide run and still have something to offer at the finish underlined his potential.

"I didn't think he'd be able to sustain it," Waller said.

"I said 'oh well it'll be a good run if he just knocks up in the last 200 metres'. I thought that'd be encouraging. To go through with it, I thought, was pretty special - it's not easy."

Start Wondering was sent across the Tasman by his owners in search of better prize money.

Waller hails from New Zealand and said while the country's racing industry was strong in many ways, its prize money levels fell short.

"They've got some great horses, they are passionate about their breeding, their racing, but they just don't have the population, they don't have the betting population and their prize money is just terrible," Waller said.

Start Wondering provided the middle leg of a winning treble for the stable after Japonisme's victory in the Group Three San Domenico Stakes and Beyond Thankful's victory in the final event.