The sand-track event featured a novel format - two one-hour cross-country endurance races followed by two 10-minute endurocross sprints - each of the four races offering $100 to the winner and points also accumulated towards finding an outright winner.
Smith won the day's opening one-hour race, the 37-year-old sending a clear message that he meant to defend his 2012 crown.
Smith finished comfortably ahead of enduro expert Callan May of Auckland, with Taupo motocross hero Brad Groombridge third.
Groombridge won the second race, finishing ahead of May and former national enduro champion Jason Davis, of Whangamata, while Smith was in fifth position, just behind seven-time and current national moto trials champion Jake Whitaker, of Wellington.
So, at this halfway stage in the competition, Groombridge held the advantage, his 3-1 results marginally better than Smith's 1-5 results. But the worst was yet to come - the endurocross phase on a course that resembled a BMX track on steroids, with logs and tractor tyres thrown in.
Smith won the first of two endurocross sprints, finishing ahead of Whitaker, Groombridge, Davis and May.So it came down to the final race to decide the outright honours.
Disaster struck for Smith at the start of race four, the second endurocross sprint, and an altercation with a tractor tyre left him at the back of the field.
Calmly Smith set about hunting down Groombridge, eventually catching his main rival and forcing his way past at about the halfway stage. When Groombridge made a mistake of his own a minute later, Smith was able to open a gap, eventually finishing the race third, behind Whitaker and Davis, with Eketahuna's Jacob Hyslop claiming fourth and Groombridge crossing the line in fifth.
This made it 1-5-1-3 for Smith (Sargent Yamaha YZ450F), worth 87 points, and 3-1-3-5 for Groombridge (Action Moto Suzuki RM-Z450), worth 82 points.
Third overall was Davis (KTM 300 XC), his 4-3-4-2 results earning him 78 points, while May (Kiwi Rider BikesportNZ.com YZ250F) was fourth, his 2-2-5-6 results earning him 75 points. Whitaker (Husaberg FE250) rounded out the top five with 9-7-2-1 results, giving him 73 points.
"I was pretty happy to be out front in the first race of the day ... no dust to deal with," said Smith afterwards. "It wasn't quite like that for race two, though, because I crashed in turn one and had to choke on a lot of powder before I could get back to a reasonable position. I was never going to give up though."