A Pierro colt has topped the first session of New Zealand's premier yearling sale at Karaka, fetching $900,000.

The colt was knocked down to bloodstock agent Garry Carvell who was particularly pleased to get the yearling out of Redoute's Choice mare Our Squeezer, a half sister to Imposingly, the dam of triple Group One winner Bonneval.

"He's by a sire who's booming and the cross with Redoute's Choice mares produces plenty of winners and stakes winners," Carvell said.

"He's a lovely horse and they aren't easy to find. When you go through the sales in Australia there were only two or three colts out of Redoute's Choice mares."

Champion Sydney trainer Chris Waller will prepare one of the other top lots with his bloodstock agent Guy Mulcaster outlaying $575,000 to secure a colt by United States Triple Crown winner American Pharoah out of Posavina.

"Chris went and saw him on Saturday morning and he loved him so we were pleased to secure him," Mulcaster said.

"He (American Pharoah) is doing a super job as they are doing it on the grass and on the dirt so to have a horse of his calibre standing down here is a real privilege.

"He is leaving super types and you won't see a horse walk like that very often."