THOUSAND OAKS, Calif. – If Justin Thomas’ trajectory continues at its current clip and he finds himself on the correct end of a trophy presentation on Sunday at the Zozo Championship, he’ll likely consider his gritty opening round the pivotal moment in the tournament.

Thomas made the turn on Thursday at even par, following two birdies and two bogeys that included a three-putt (No. 7), a lip out (No. 2) and a birdie attempt that stopped one roll short on the first hole. In the past, those 15 putts would have carried over to his second nine but not on Thursday.

Thomas started working with putting coach John Graham during the FedExCup Playoffs and the focus has been on improving his feel on the greens and his green reading. He also wanted to improve his ability to adjust his play on the greens during a round and on Thursday that work paid off.

He played the second nine on Day 1 in 7 under par, thanks to 12 putts, and now holds a one-stroke lead following a second-round 65.

“I called [Graham] on the way home and he said, ‘I'm proud of you, that was a big day,’” Thomas said. “I feel like there's many, many times when I've had a front nine like that in the past where I'm maybe not putting poorly, I'm just making nothing, and then I continue to do that on the back instead of continuing to try to feel like I can make everything and stay in my process and start making some putts.”

Thomas has three top-15 finishes since he and Graham started working together, including his runner-up finish at the Tour Championship and an eighth-place showing at the U.S. Open.