Brooks Koepka fired an eight-under 63 to trail leader Taylor Moore by one shot in the first round of the The CJ Cup Byron Nelson in Texas.
Four days on from the conclusion of the PGA Championship, won by Englishman Aaron Rai, regular tour action in the US resumed at TPC Craig Ranch with world No 1 and defending tournament champion Scottie Scheffler headlining the field.
But it was former No 1 and five-time major winner Koepka, looking for his first victory since returning to the PGA Tour from LIV Golf, who made the more eye-catching start in McKinney thanks to a bogey-free opening round featuring six birdies and one eagle.
Starting from the 10th hole, Koepka birdied the par-four 11th before finding an eagle at the next hole, the par-five 12th. After a further birdie at the 14th helped him go out in a four-under 31, the American birdied the second, fourth, fifth and sixth on his way in for a round of 63.
Koepka has returned to the PGA Tour this year after four seasons on LIV Golf and has so far recorded a best finish of tied-ninth at the Cognizant Classic in February. He finished tied 55th last week at Aronimink after sliding out of contention on the final day with a 74.
"Finally, I felt good with the putter," said Koepka. "I felt good the last few days with it when I was working in my studio. Then when I got here, it felt very comfortable.
"Just happy with the way everything went today."
Moore, whose only win in his first 128 tour starts came at the 2023 Valspar Championship, made a 14-foot birdie putt from the fringe on the par-5 ninth to finish the best round of his tour career.
The Texas native and Oklahoma resident leads Koepka and Jesper Svensson, who had a chance to join Moore atop the leaderboard but missed a 9-footer on the ninth.
Texan resident Scheffler, who won last year's tournament on 31 under par to equal the record for the fewest amount of strokes in a PGA Tour event, opened his title defence with a five-under 66, while playing with Koepka and Si Woo Kim, one of seven players at 64.
Scheffler birdied the 12th and 13th before finishing his day by going three under through his final five holes, including a round-ending birdie.
"I felt like I was getting lapped out there for a little bit," said Scheffler. "So I was fortunate to make a couple of birdies late in the round and keep myself in the tournament.
"I feel like sometimes in these tests, once you start getting behind, you can start falling pretty far behind, and it can be difficult to catch up. It was nice to stay in it.
"Overall, it was a fun group. We had good momentum in the group the whole day. Brooks played great, and Si Woo played really nice as well. Hopefully more of that the next couple of days."
Watch the The CJ Cup Byron Nelson live until Sunday on Your Site Golf, where Scottie Scheffler is the defending champion. or .
