"The day started well and continued to look good, until I had that little slip-up," said Lamont.
"I hit a tyre and got out of shape, then hit a trackside barrier. I was three seconds clear of Columb before that. "I was hoping to go away from here with a nine-point lead ... I'll just have to be happy with three.
"I have been working hard on my starts and that certainly worked better for me than at the Woodville GP [an event he also won, a fortnight earlier].
"Norm Cobb has done a brilliant job with my suspension and with helping out in the pits. He's been a great support. Now I'm looking forward to racing on my home track at Tokoroa in a couple of weeks."
Visiting Australian rider Jay Wilson took the third step on the MX2 podium on Saturday, 14 points behind Columb.
The four-round series heads to Tokoroa for round two on February 23. Round three follows in Pukekohe on March 9 before the series wraps up in Taupo on March 22.