The Queenstown-based defending MX2 champion, riding his two-stroke YZ250, was on track for the class overall win at the fourth and final round in Taupo on Saturday, but suffered a minor set-back in the final moto to end the day third.
Columb closed the series fourth overall - the first time he has finished off the podium in a national series in 11 years.
''It's frustrating, but I gave it my all and I was happy with my riding,'' Columb said.
His day had started off well with a third in the first moto, followed by a second in the next race.
Then he grabbed the holeshot in the final moto of the season and put the hammer down. Unfortunately, an electrical issue with his bike shunted him backwards to finish the race fifth.
''It really summed up my year of New Zealand championships, as just being a lot of bad luck,'' he said.
Columb planned to keep training for selected races over winter and the possibility of a call-up to an international team, if it had an injured rider.
In the premier class, Cody Cooper continued his domination. The Mt Maunganui rider took his Honda CRF450 to 1-1-3 results in the MX1 races, easily wrapping up the crown for a second consecutive season.
So convincing was his win that he finished the four-round (12-race) series 51 points clear of his nearest challenger, Billy MacKenzie, from Scotland.
In the MX2 class, Mangakino's Kayne Lamont realised a career-long dream of winning his first major senior national title.
Lamont had been on the operating table at Rotorua Hospital on the Thursday night before Saturday's racing having his appendix removed, and it was a heavily-strapped and bandaged Lamont who lined up to ride in Taupo just two days later.
In substantial pain, he opted out of the series final MX2 moto but still finished the championship 11 points ahead of Dargaville's Hamish Dobbyn (KTM).
Two reigning national junior champions dominated the series in the 125cc class. Hamilton's 2013 junior national 12-14 years' 125cc class champion Josiah Natzke led by a healthy 35-point margin at the start of racing in Taupo and soon extended that to 74 points by the end of the afternoon.
He won his first senior title ahead of 2013 junior national 14-16 years' 250cc four-stroke champion Hadleigh Knight, of Atiamuri.
