Robbie Laing wasn't swayed by the pedigree page in the sales catalogue when parting with $500,000 to purchase Caulfield debut winner Missrock.

Laing was taken with the appearance of the daughter of Fastnet Rock, so much so he thought she was a colt.

Missrock scored an impressive victory coming from back in the field to score in the Debutant Stakes (1000m) on Saturday.

Ridden by Mark Zahra, Missrock ($26) scored a three-quarter length win from Pearl Congenial ($4.60) with Valliano ($31) a long neck away third.

"I hadn't picked her out at the sales, I just saw her and thought that's a lovely colt, then she lifted her tail up and it was a filly," Laing said.

Laing thought the filly would bring $1 million when she went through the ring and when bidding stopped at $450,000, he piped in, securing her for $500,000.

It's only the second time Laing has gone to $500,000 for a yearling, having previously purchased the subsequent Group winner Danerich in 2004.

Laing said the filly would head to the Maribyrnong Plate at Flemington over the Melbourne Cup carnival before going for a break.

"She's the star filly of the team and when you pay half a million dollars, it's a weight off the shoulders when they win on debut," Laing said.

"She's in the Magic Millions, but you go up there, get a 40-degree day and you draw 18, it's a long way home.

"Well go for the Maribyrnong Plate and then after Christmas bring her back for the Blue Diamond Preludes."

Laing said he has hopes of returning to Caulfield in 12 months to contest the Thousand Guineas.