Lydia Ko opened the 2026 Mizuho Americas Open with a five-under 67 on Thursday at Mountain Ridge Country Club, riding a brand-new Scotty Cameron putter to a share of second alongside Jeeno Thitikul, one shot behind first-round leader Andrea Lee.
The LPGA Hall of Famer's round was anchored by an eagle on the par-5 13th, but it was the rediscovered touch on the greens that lit up her interview after the round. Ko has been on the phone almost daily with Scotty Cameron's master craftsman Paul Vizenko in the lead-up to this week, and the work paid off in West Caldwell, New Jersey.
"I actually putted really well, which was a nice change," Ko said. "I haven't putted well since I shot 60. And that day I had a new putter, and this week I have a new putter. So I don't know if it's like a one-off honeymoon phase, but I'll take it, regardless."
The new flat-stick is a significant departure from the model Ko has trusted in recent seasons. The plumber's neck design is a shape she hasn't carried in her bag for seven years, and the visual change took some adjusting on Mountain Ridge's notoriously slick surfaces.
"It was a pretty big change having a putter with a completely different hosel. I have a plumber's neck, and I haven't played a plumber's neck putter since 2018 and early 2019. So it's visually very different," Ko said. "But I feel like even though it might take time for me to get used to the new putter and the new look, I thought that in the long run it's beneficial. To see a lot of the hard work kind of pay off on a tricky golf course like this is really rewarding."
Ko praised the team behind the switch, including her putting coach Chris and swing coach Sean, while joking she has practically put Vizenko on speed dial. She also leaned on Scotty Cameron tour representative Tom for fittings on the road.
"The greens are very undulating and tough, so I feel like you need to be really smart in where you leave your second shots," she said. "I think you just have to know which side is a better side to miss. If you are in between clubs, if short is better, kind of erring more on the shorter club. And if you can be aggressive, try and take advantage of that."
Ko compared the speed of the putting surfaces to the greens at Lancaster Country Club, where the LPGA staged the 2024 U.S. Women's Open. "There are some putts that you're aiming so far out that the hole is not even in your peripheral vision anymore," she said. "It kind of reminds me a little bit of Lancaster Country Club, where we played the U.S. Women's Open a couple of years ago. That was some of the slopiest and fastest greens I had played on. I did not putt well there."
The 67 leaves Ko well placed for a first LPGA win since her wave of victories last summer, and tied with world No. 2 Thitikul, who shared second on a day when defending champion's host Michelle Wie West shot 82 in her competitive return. Andrea Lee leads on six-under 66 with Round 2 set for Friday.