"It's a hard race, not only because of the winning and losing but also because you can get quite beat up on this course. It's really technical and after four minutes, your lungs are hurting and it's easy to make some big mistakes.
"None of the overseas paddlers had seen the river this high and it was a real shock when we came through the crux section - where the whole river is pinched up into a 1m gap - and saw just how much water there actually was.''
Dawson finished five seconds ahead of American Dane Jackson, with another local paddler, Isaac Levinson, third in 4.19.
But Dawson didn't come away completely unscathed - he and Olympic silver medallist Vavra Hradilek teamed up in a double boat.
"Looking at the high flows, we almost backed out of the race but we ended up going and crashed really bad in a 6m drop. I snapped my paddle and bailed out of the back of the boat, leaving Vavra on his own, before swimming over another shallow waterfall and getting pulled to the bank by the rescue crew. That's definitely not something that's happened to me before.''
The win caps a memorable year for Dawson, adding to his win in the Teva Mountain Games earlier this year, his 15th-place finish in whitewater slalom at the London Olympics and his third-placing at the Sickline world championships last month.
Fellow Kiwi Louise Urwin also finished third behind USA's Adrienne Levkenkt and Katrina Van Wijk (Canada) in the women's race.