Blake Shinn has notched his first Group One win in New Zealand aboard two-year-old Summer Passage at Ellerslie.

The Sydney jockey stepped in to ride the Lance O'Sullivan and Andrew Scott-trained colt in Thursday's Sistema Stakes because Zac Purton was unavailable when the washed out meeting was transferred from Saturday to Thursday.

Purton's week could not have been much worse with the Hong Kong-based jockey now ruled out of Saturday's Golden Slipper meeting in Sydney because of an ear infection.

"He's an exceptional two-year-old and it's a big thrill to get my first Group One winner overseas," Shinn told Trackside.

"I'm delighted to have got the opportunity to ride such an exciting horse."

"I didn't expect to be here today and I feel for Zac who has missed out due to unfortunate circumstances."

Connections will now decide whether to take Summer Passage to Sydney for the Group One ATC Sires' Produce Stakes at Randwick on April 1.

"We'll talk to Blake and the owners and then make a decision. It's certainly on the radar," O'Sullivan said.

Shinn finished out of the money on Gentil Tonton in the Group One Auckland Cup won by the Tony Pike-trained Chenille.

Pike said he would assess the mare over the next week before deciding whether to give her a chance in next month's Sydney Cup, also over 3200 metres.

Shinn has four Group One rides at Rosehill on Saturday including Pariah in the $3.5 million Golden Slipper.