He pushed his rivals all day and secured second in the first two races.
Columb then won the final moto to finish second on the event's podium, leaving him three points shy of the overall lead held by South Waikato's Kayne Lamont.
While a win was always preferable, Columb was happy with his fitness and the way he rode, ''but Kayne rode better,'' he said.
''He's probably my biggest threat.''
The dry and dusty conditions meant Columb's front wheel struggled to find traction, so his Altherm JCR Racing Yamaha team has made changes to his forks ahead of the second round in Tokoroa next Sunday.
A mere six points separate the MX1 class leaders, with defending national champion Cody Cooper finishing just three points ahead of Queensland rider Ford Dale, and Edinburgh's Billy MacKenzie on the third step of the podium, only three points further back.
Returning to racing after a seven-month break due to a concussion incurred while racing in the United States last year, Palmerston's Duncan finished Saturday's three 125cc class motos 3-3-5. The results were good enough for fourth overall.
She qualified in the No 1 position and shot into the lead at the start of the day's first 125cc race, before eventually being bumped back to third spot, behind Hamilton's Josiah Natzke and Tauranga's Aaron Wiltshier.
Duncan again finished third in the next race, this time behind Te Puke's Logan Blackburn and Natzke, and a podium finish for the day was looming large.
Then, in the third and final 125cc race, she was again among the leaders when she ''made a silly mistake and went down,'' Duncan said. She had to settle for fifth position at the chequered flag, with her overall points four behind the third-ranked Wiltshier. Fellow Yamaha ace Blackburn heads the 125cc standings.
Oamaru's Joel Meikle was competing in his first MX2 race on Saturday when he crashed, dislocating a knuckle and breaking his finger. A trip to hospital ensued and he now has it in a cast, ruling him out of the following three rounds.
Meikle (16) will now focus on recuperating in time for the national junior championships on the West Coast in April.
Campbell King, of Dunedin, is recovering from a foot injury sustained at the New Zealand Motocross Grand Prix in Woodville last month and elected not to race on Saturday. He is hoping to ride in the final two rounds.
After Tokoroa, the four-round series heads to Pukekohe on March 9, with the final round in Taupo on March 22.
