It is usually par-74 but two of the short par-5s have been converted to par-4s as the field tee off a mixture of men's white and women's yellow tee boxes.
The women's course record off the yellows is 4-under 70, jointly held by two players.
Kobori's 68 is the lowest score by a female player in the course's illustrious history, surpassing professional Marilynn Smith's 69 off the men's tees in April of 1964.
“I managed to keep the ball in play pretty much the whole day and I hit lots of greens and holed a few putts,” Kobori told NZ Golf after her round.
“The whole day went pretty smoothly, which was nice. Everything seems to be coming together really nicely at the moment.”
Kobori was two strokes clear of Wanganui's Tara Raj, with Titirangi's Fiona Xu a shot back, as many of the field found the front nine much less challenging than the home stretch, which ends with six consecutive par-4s.
Brettkelly modestly described his flawless 7-under 65 as a solid day at the office.
The Canterbury men's strokeplay champion, who hails from the small rural course of Hororata near Christchurch, had seven birdies and 11 pars to hold a two-stroke advantage over fellow Cantabrian Zach May, Wellington's Jayden Ford and Palmerston North's Tyler Wood, who birdied five of his opening six holes and was 6-under after 10.
“I've been struggling mentally on and off the course for a few years,” 21-year-old left-hander Brettkelly said. “And in the last three or four months I've started to feel my golf game and my confidence start to come back.
“It's nice to get a good round and it's been feeling decent in the last few events, but this is the best I've felt mentally.”
Brettkelly joined a select group of players, including European tour pro Ryan Fox, to have shot 65 off the championship tees at Poverty Bay.
The course record is 64 held by Hawke's Bay pro Pieter Zwart.
Thirty of the 97 players went under par yesterday.
The 27 males in red figures had an eye-opening combined total of nearly 140 birdies.
“Everyone took advantage of the benign conditions. “Conditions were perfect for scoring,” said tournament director Dave Mangan.
There was a touch of weather-related drama in the afternoon, when nearby thunder and lightning forced a short stoppage of play.
“But there was not a drop of rain on the golf course,” said Mangan. “When the lightning got very close we were looking at the radar, and we suspended play for about 20 minutes.”
Defending champion Sam Jones, of Taranaki, opened with 70 but was upstaged by younger brother Ethan, who shot 68.
With today dawning fine and only a hint of wind, scoring was expected to again be hot.
The top 32 male and top 16 female players after 36 holes of strokeplay qualify for matchplay to decide the overall champions.
