Te Akau Racing's stranglehold on the Karaka Million two-year-old race has extended to its fourth consecutive year with Cool Aza Beel taking out the million-dollar feature at Ellerslie.

New Zealand's racing powerhouse began its run with Melody Belle in 2017 and followed with Avantage and Probabeel.

"It's awesome," trainer Jamie Richards said. "It's a really great way to start the biggest week of the year for us.

"Whether we can make it five in a row I'm not sure, but I'd like to think so. We're definitely going to be out there in force at Karaka (sales) over the next few days, looking for more horses like this."

Te Akau's four successive winners have been ridden by Opie Bosson with Cool Aza Beel beating Play That Song and Taroni.

"I saw the favourite's head come up beside me, but I have to give credit to my horse - he gave a really good kick in the straight," Bosson said. "It's a great result and a privilege to be part of the Te Akau team."

"We've always had a lot of faith in this horse," Richards said. "We took our time with him.

"We'd been really happy with his work coming into today. It's been a great effort by the team at home with this horse, and a great ride by Opie, who's just a freak."