The 27-year-old amateur fired a four-under par 68 to grab one of two places up for grabs from the 30 golfers at the final qualifying at Cromwell.
Young Australian Daniel Gale, who only turned professional this month, topped qualifiers at Cromwell with a five-under par 67, followed by MacLachlan on 68, a shot ahead of Auckland’s Kevin Koong with local Queenstown junior James Anstiss and Frenchman Victor Riu on 70.
Meanwhile Christchurch senior Peter Brinsdon and Taranaki professional Brad Hayward shared top spot at the other final qualifying event at Paraparaumu Beach on the Kapiti coast.
They fired four-under par totals of 67, joined by Australian professionals Nick Flanagan and Clayton Bridges who both shot 68 to be the four qualifiers from 51 starters at the Wellington event, played in windy and wet conditions.
MacLachlan, who moved to Queenstown three years ago working in the family forestry operation, plays representative golf for Otago after playing for Wellington in his early golfing days.
The Plus-1 handicapper thought he had blown his chances after he made a double bogey at the par-5 15th hole but he managed to birdie the final three holes to finish on 68.
“Honestly I thought I was over it after the double. Even after the birdie on the last I thought I had missed. But this is a dream come true, to play in the New Zealand Open and on your home course.”
He won the regional qualifying event in Dunedin which he thought was “a fluke” but decided to play some rounds at Cromwell to get used to the course.
“We have had a lot of rain which softened the course and made it more scoreable if you play well. That back nine was interesting. I made six birdies, a bogey, a double and one par.”
MacLachlan, who lives at Millbrook and plays often with local professional and NZPGA winner Ben Campbell, expects a few of his mates will head to the Open to support him, although he suspects that would be on the weekend.
“That will be my first goal, to make it through to the weekend. It is going to be a lot of fun.”
Many of the field in the other qualifying event on the Kapiti Coast had competed at the NZPGA Championship in Palmerston North, before venturing south to take on the tough links course at Paraparaumu Beach in challenging conditions.
Brinsdon, the former Wellington Golf Association executive director, produced arguably the round of his life, with five birdies and a single bogey in his four-under 67.
His round was mirrored by Hayward who reeled off four straight birdies on the front nine mixed with a bogey and a birdie coming home in his 67.
There was significant interest in the efforts of former PGA Tour player Nick Flanagan from Australia who blasted five birdies in six holes in the middle of his round, holding on with a late dropped shot in his 68, equalled by Clayton who bagged three birdies in a bogey-free round.
They finished two shots clear of New Zealand’s Nick Loach who was a shot ahead of a eight players on 71.
Flanagan was a blue chip prospect, winning the US Amateur and going on to enjoy six professional victories including four on the Nationwide Tour, now the Web.com Tour, earning him promotion to golf’s big dance on the PGA Tour.
But a thumb injury, that required surgery, hindered him for two years, and a back injury suffered as a kid came back to haunt him.
“I just wasn’t able to play consistently without injury issues. I have basically lost most of my playing rights and at 33 years old I am basically starting again,” said Flanagan. “That is harder when you are older and motivation is a challenge with Monday qualifying.
“I played at The Hills twice when the Nationwide was there. I am playing quite solid and for the last 12 months I’ve not had any injury issues. This is a good opportunity for me to do well. My irons were good today but I will need to do some work on my driver but I am looking forward to the New Zealand Open.”
The 99th ISPS Handa New Zealand Open, co-sanctioned with the ISPS Handa PGA Tour of Australasia and the Asian Tour, begins on Thursday at Millbrook Resort and The Hills, with a cut for the top 60 players plus ties to contest the final two rounds at Millbrook Resort.
Leading scores, Cromwell Par 72 (2 to qualify):
67 Daniel Gale (AUS)
68 Fraser MacLachlan (Millbrook, Am)
69 Kevin Koong (Muriwai, Am)
70 James Anstiss (Wakatipu, Am), Victor Riu (FRA)
Leading Scores, Paraparaumu Beach, par 71 (4 to qualify):
67 Peter Brinsdon (Pegasus, Am), Brad Hayward (NZL)
68 Nick Flanagan (AUS), Clayton Bridges (AUS)
70 Nick Loach (NZL)
71 Peter Cooke (AUS), Anthony Marchesani (AUS), Tyler Hodge (Levin, Am), Fraser Wilkin (Royal Auckland, Am), Bradley Doherty (AUS), Taylor Cooper (AUS), Kris Mueck (AUS), Hayden Webb (AUS).