Taking advantage of benign conditions, Koepka mixed four birdies, three bogeys and an eagle for his 3-under 69, while Thomas fired a 68 to sit four shots off the early lead.
Koepka, the defending champion, hit 12 of 14 fairways and 14 greens, but he missed a couple of short putts that kept him from cutting into the lead.
Thomas’ round was slightly more erratic, but he was a perfect 5-for-5 in scrambling. Thomas found the green on the par-3 13th, but he opted for a wedge from long distance, his ball clanking off the flagstick as he tapped in for par.
— PGA TOUR (@PGATOUR) October 17, 2019
“To putt it, I had to be so perfect – I would two-putt probably one out of 10 times,” Thomas said afterward. “Chipping it I felt was a lot easier. I could take a lot of the slope out of it and land it past it.”
Overall, Thomas said it was a “decent” start as he looks to win the CJ Cup for the second time in three years.
“I feel like I played a lot better than my score showed,” Thomas said, “but just a good start to the week.”