Brooks Koepka and Danny Lee figured out Bethpage Black on Thursday while the rest of the golfers just tried to survive the course.
Koepka shot a 7-under 63 to finish the day in sole possession of the lead while Lee shot a 6-under 64 to end up one shot back.
The rest of the field is at least three shots back of Lee as Tommy Fleetwood sits in solo third at 3 under and five other golfers are tied for fourth at 2 under.
Koepka had everything working during his round, especially on the greens as he made seven birdies to go with no bogeys.
"I had good reads on it all day," Koepka told a press conference. "The speed control was very solid.
"I felt very comfortable with the putter after a couple of changes we made, and very pleased with the way I putted today."
Brooks Koepka birdies his final hole to shoot 63 and leads the #PGAChamp by four. 🤯 pic.twitter.com/HAnDeKEDV7
— PGA Championship (@PGAChampionship) May 16, 2019
Lee's performance might have been the most surprising of the afternoon.
His score put him one shot back of Koepka which is much different than his previous major performances.
In nine career major appearances, he has made just four cuts. His round was very different on Thursday though as he made eight birdies to go with two bogeys on the day.
"Well, at first, I wasn't hitting it far enough to compete out here on the major championship — PGA Championship or U.S. Open. Masters I might have had a chance. But now I'm definitely hitting it further," Lee told a press conference.
"I can carry my driver about 290, 295 in the air. That's a huge bonus for me. And that was actually the first time I actually got to play in a major with this distance. I'm actually interested in myself what I can do out there this week."
"Head still. Down it goes." Danny Lee is just 2 back.#PGAChamp pic.twitter.com/MwYln2kohc
— PGA Championship (@PGAChampionship) May 16, 2019
Several notable players sit at 1 under for the tournament as Phil Mickelson, Dustin Johnson, Jason Day and Jordan Spieth all shot rounds of 69.
Tiger Woods sits nine shots back of Koepka at 2 over.