Soffe competed in the over 50 master two category and bench pressed 217.5kg to claim the title.
Soffe, who has been powerlifting since 2003, said he was thrilled with the result and celebrated with a few beers on Saturday night.
It is a 2.5kg improvement on Soffe's personal best in the weight class.
The 51-year-old has been lifting weights since he was 15.
Other national records went to Canterbury's Leighton Best, who competed in the open 105kg class. He set a national record with a press of 230kg.
The biggest lift of the day went to Auckland's Jason Cunningham Gerbich.
Girbich, competing in the open 120 plus kilogram class, set a national record with a bench press of 257kg.
Dunedin woman Sylvia Clarkson won the women's master three class with a personal best of 55kg.
Otago Amateur Weight Lifting Association president Marie Soffe said the event went extremely well, with about 100 attending across two sessions, and boded well for next year, when Dunedin will host the New Zealand National Powerlifting Championships.
Twenty-four men and seven women competed in the event.
