The overnight leader’s 5-under-par 66 on Saturday was highlighted by an eagle at the short par-4 12th hole, a blind wedge shot from 66 metres out that took two bounces before spinning back into the cup.
At 22-under-par after 54 holes, it will be Koh’s tournament to lose on the final day on Millbrook Resort’s composite course as he tries to become the event’s second consecutive Asian winner.
The closest challenger to the four-time winner on the Korean Tour is West Australian Ryan Peake, who made up two shots on the leader with a 64 today and has the biggest day of his career ahead on Sunday.
Japan’s Kazumi Higa eagled the par-5 first and 17th holes to climb to a share of third with a 9-under-par 62.
He is joined in the group five shots behind by South African Ian Snyman (66), China’s Bobby Bai (67) and Challenger PGA Tour of Australasia Order of Merit No.1 Elvis Smylie, who made up plenty of late ground with a back nine of 29 in a 6-under 66.
The leading New Zealander is Sam Jones who charged to a share of seventh, seven shots behind, thanks to a composite course record round of 10-under 61.
He was close to finishing his round when Koh was getting his underway with a three-shot lead, the Korean quickly building on his advantage with birdies at the first, second and third holes.
Although he had two bogeys, he turned in 3-under 33 and was as many as six shots in front before his lead dwindled slightly with six consecutive pars coming home after his eagle on 12.
“I was concerned about how much backspin I’m going to have after the shot, but it just went perfectly,” Koh said of his second hole-out in as many days.
“It’s great that I have a four-shot lead, but this course itself is very scoreable, so I need to keep focused on what I’m doing and just make sure I just stay consistent to what I’m doing.”
Despite climbing to second and being bogey-free for 39 holes, Peake is seeking more consistency from his driver. He headed to the driving range post-round looking for some solutions after hitting just three out of 14 fairways today.
“It’s not the flight I want. I’m not getting the distance that I want and I’m just not finding a lot of these fairways,” Peake said.
“When you get in some of this long rough, it’s hard to get it close and give yourself reasonable birdie opportunities.
“I’m doing well to make a score from where I am, but yeah, I just need to start hitting some fairways.”
The winner of two events on his home tour this season, Smylie was stuck in neutral on the front nine but erupted with four birdies and an eagle on the back nine, turning a 10-shot deficit to the leader into a more manageable six.
He’s confident that he’s close enough to chase down Koh.
“It’d be special to be able to come back from how many shots I am behind the leader, but I know that I can do that and it’s definitely motivating,” the Australian PGA champion said.
Jones’s brilliant 61 included eight birdies plus an eagle on the par-5 17th hole where his second shot with a 7-iron finished 4m from the cup and he rolled in the slightly uphill putt.
He admitted his low round was something of a surprise.
“It’s been a bit rough out there the first couple of days. I struggled a little bit on the greens, haven’t been swinging it great. But yeah, that’s golf,” the lefthander from Manaia Golf Club said.
“I was just pretty grateful to be teeing it up today. I was right on the cut line yesterday.”
Fellow Kiwi Mark Brown also made a sizeable move on day three with a 65 lifting him inside the top 20, setting the 50-year-old up for potentially his final round at the New Zealand Open presented by Sky Sport.
“I want to to play myself in and not take up an invite that could go to a younger player. So tomorrow could be my last time at the New Zealand Open,” said Brown, who was runner-up in 2014, the first year of the Pro-Am format.
He has no serious thoughts of playing the PGA TOUR Champions like countryman Steve Alker, but may head to the European Staysure Tour.
“I get one-year exemption on the (European) seniors tour courtesy of winning on the tour, so I may take up that option more for experience and travel to Europe with my wife,” he said.
While the home crowd hoped for a big Saturday charge from Millbrook member Ben Campbell and former champion Michael Hendry, the duo lost ground on the lead.
They are both at 10-under, and 12 shots back, after Campbell carded a 69 and Hendry a 71.
Round 4 of the 104th New Zealand Open presented by Sky Sport tees off tomorrow morning at Millbrook Resort.
