A field of 12 will contest Perth's biggest sprint race, the Winterbottom Stakes at Ascot.

Saturday's Group One race over 1200m has attracted five eastern states visitors who will tackle seven local sprinters.

The field is headed by the Joe Pride-trained Terravista who is coming off a last start second to Redzel at Flemington.

Last-start Darley Classic Classic winner Malaguerra joins Terravista along with Takedown and the Lindsay Park pair of Keen Array and Sheidel in trying to take the Group One contest after local galloper Scales Of Justice won the Group One Railway Stakes on Saturday.

The Chris Gangemi-trained Rock Magic is the highest-rated local galloper having won two of his past three starts.

Malaguerra is the $3.20 favourite in early markets ahead of Terravista at $3.60 and the Gary Moore-trained Takedown at $7.50.