He told reporters: "I've had a couple of top-10s in majors and I feel like I've learned a lot over the years playing quite a few majors now". It was fitting that the Dane was there - his first name means thunder bear.
CHARLOTTE, North Carolina: Denmark's Thorbjorn Olesen and American Kevin Kisner each closed with birdies Thursday to share a one-stroke lead at the PGA Championship while Jordan Spieth and Rory McIlroy stumbled in quest of golf history.
"I'm hitting the ball really nice and things are going my way".
Kisner built himself a pretty comfortable cushion thanks to a chip-in eagle on the par-5 seventh hole.
For better and worse, Day is a rhythm player.
"The first 15 holes, especially, I was driving the ball very, very well, and that made it a bit easier", said the world number 78, a four-times European Tour victor. In a group two back was Tony Finau, who turns heads on the driving range with his length.
Other afternoon starters include United States stars Rickie Fowler and Phil Mickelson, Spain's Jon Rahm and England's Justin Rose.
Koepka overpowered Erin Hills in Wisconsin to win the U.S. Open in June.
There's also something to be said for Kisner's ability at overcoming the obvious at Quail Hollow. He and the other bangers have the ability to take more aggressive lines off the tee - over trees, for instance - that shorten holes immensely. I haven't hit it this well this whole summer.
"It was tough to hole putts", McIlroy said. "The key around here is keeping the ball out of the fairway".
He headed into the back nine at one under par after three birdies in the first half of his round, but a bogey at the 13th and a double bogey at the 14th left him scrambling to save his round, with four straight pars leaving the Irishman wanting more.
Matsuyama was having a bogey-free round and started his attack with an eight-foot birdie putt at the par-4 fifth.
World number two Spieth, chasing his fourth career major title and completion of a career Grand Slam, would become the youngest player, at 24, to win all four majors at least once if he can lift the Wanamaker Trophy this weekend. You expect to play those holes in even or under par and if I had done that, my scorecard would gave looked very different.
"If I was truly free, I wouldn't have cared", he said.
Keep track of how they're all getting on with our leaderboard. He made a 10 on that hole, later explaining his actions during his walk to the parking lot by saying "it shows you care, that's all". I have a week to work on it and see if I can get it dialed in.
For all the talk about this 7,600-yard course favoring the big hitters, the shortest club in the bag turned out to be just as valuable.
Last month he shot 70-77 at Royal Birkdale to miss the cut in the British Open.
The grain of the greens was causing havoc, the speed of the greens was causing headaches.
"I thought to myself: 'They are not giving birdies at all. I'm loving playing right now".