King won the class previously in 1989, 2006 and 2007.

But, while his successful title defence on the YZ125 two-stroke was perhaps never in doubt, King faced a much sterner test in the MX1 (open) class where he started the day in New Plymouth with a four-point deficit.

Tauranga's Peter Broxholme led the class and King knew he'd have to beat the Honda rider twice on Sunday to snatch away his first MX1 crown. And that's exactly what King did, enough for him to tie on points with Broxholme and yet win the title on a count-back because he had a superior race record.

"It's a dream come true for me," said King afterwards. "I've won the 125cc title four times now, but never the open class. A few riders made mistakes and that helped but I still had to do the job.

"Now I'm a double champion in one season ... I'll never forget this.

"It's getting harder each year for me though. These young guys are getting faster and faster. I might not be able to beat them next year. "My brother Darryll (the Subway Yamaha team manager) helped me immensely this year. He's been there and won titles before so he knew what to do.

"The YZ125 was so strong and so much fun to ride. But I don't know yet whether I will be defending both titles next year or just one ... maybe I'll step aside completely and let the young guys come through."

The MX2 (250cc) class was won by Hawera's Daryl Hurley (Suzuki) after series leader Michaedl Phillips (Honda) crashed out of the final race of the series.