Tom Walsh's 13-year reign as national shot put champion is over after he was beaten by long-time rival Jacko Gill in Wellington.
Gill went close to his personal best with a 21.80m heave to eclipse two-time Olympic bronze medallist Walsh, whose best on Saturday was 21.25m.
Former junior world champion Gill, 28, attributed his form and maiden national championship title to progress made in training sessions with parents Nerida and Walter, who are both former national throwing champions themselves.
Gill began with a 21.27m effort at Newtown Park and steadily increased his distances, throwing 21.44m and 21.75m before hitting his longest distance.
An out-of-sorts Walsh produced his best effort came with his second throw but he failed to improve over the four remaining rounds.
Elsewhere, pole vaulter Eliza McCartney tasted success in her first national championships appearance for six years.
The Rio Olympics bronze medallist shook off a succession of injuries over recent years to clear 4.61m and beat defending champion Olivia McTaggart and Commonwealth Games bronze medallist Imogen Ayris, after the trio engaged in a tightly-fought battle.
McCartney said she felt "really, really good" despite falling 10cm short of the height needed to qualify for the world championships.
"It's been many, many years since I've competed at nationals and to be out here, I'm just really grateful that I get to do it again and to have a really competitive pole vault - that was amazing," she said.
"We were jumping with each other, we were able to egg each other on and have a really cool environment and I don't know if I've had that in New Zealand before, so it was a really cool champs to come back for."
McCartney was competing against McTaggart and last year's Commonwealth Games bronze medallist Imogen Ayris, who all cleared 4.46m then lifted the bar another 15cm.
Earlier, Cantabrian Hamish Kerr retained his national title in the men's high jump with a winning height of 2.20m, well below the national record he set in Europe last month.
Kerr said: "Another national title sums it up, the height wasn't what I've been doing the last few weeks. I moved the bar up from 2.20m to 2.30m, which was fighting words from me and it was a statement from where my jumping was at, but I'm just stoked to be here and I've done a lot of travel in recent weeks. I'm looking forward to putting my feet up and re-building for the rest of the season."
Despite the cold and damp morning conditions, Paralympic champion Lisa Adams put on a demonstration of excellent throwing to win the women's Para shot put with a season's best 15.19m.
