Armstrong leapt out ahead of Jerry Zhu in their first top-16 run and was handed the easy run into the top eight after Zhu straight-lined the course. He then continued his charge through to the top-eight as he swept past Troy Jenkins.
The final battles were set - Armstrong and Daynom Templeman battled for the win, while Nico Reid and Joe Marshall scrapped for the final podium spot.
Reid looked odds-on to win the battle for third until he went too hot into turn two, skating off the track into turn three, handing Marshall the third for the round.
In the final battle of the weekend, Armstrong faced Templeman for outright honours.
Armstrong led Templeman in the first battle and was judged to have clipped every zone.
As he chased Templeman, he struggled to see through the smoke coming from the 1000 horsepower BMW M3. However, he made it out the other side having hit all the clips the judges desired, while running close to the rear of his rival.
The judges duly gave Armstrong overall victory and with it the 2016-17 Demon Energy D1NZ National Drifting Championship.