As thrilled as Waikato Stud boss Mark Chittick was at becoming the top seller at Karaka for the first time, part of his mind was on his absent wife.

With a draft most rated as its strongest ever, the Matamata-based stud sold 46 yearlings for an aggregate of $NZ7.655 million ($A7.28 million) - more than $1 million clear of perennial sale-topper Cambridge Stud.

But Chittick, who took over the running of the stud from his father Garry in August 2012, was thinking of his wife Lisa, who is battling illness.

"I'm very emotional right now because I'd love to have my best mate here to share this with," Chittick said.

"But at the end of the day, tough times don't last, tough people do."

Waikato Stud earned its place at the top with a strategy which has involved only standing stallions it has significant equity in, rather than northern hemisphere shuttle stallions which can disappear to another stud at the whim of their owners.

They have also focused on stallions which have performed in the Australian and Asian market.

They inherited O'Reilly when they bought Waikato Stud, and they have since secured successful sires Pins and Savabeel, and this season they secured Cox Plate winner Ocean Park.

Chittick said the decision to concentrate its yearlings on Karaka was a factor, but the quality was also very high.

"There's no doubt about it, it was our best draft ever," he said.

"There's a whole lot of people to thank, and there's a whole lot of people involved, but most of all Pins, O'Reilly and Savabeel."

Waikato Stud's biggest seller was a Savabeel-Splashing Out colt, bought by David Ellis for $500,000.

After 32 years of being leading seller at New Zealand's premier yearling sale, Sir Patrick Hogan's Cambridge Stud finished second in 2013 and again this year when it sold 34 yearlings for $6.345 million.

Cambridge did however sell the most expensive yearling, an $800,000 Fastnet Rock-Katie Lee colt bought by Katie Lee's trainers, Graeme and Debbie Rogerson.

Hogan said it was a relatively successful sale but that prices in the middle to lower market were probably affected by the weaker Australian dollar compared to last year.

Ellis dominated buying, securing 35 yearlings for $6.42 million.