ATLANTA • Xander Schauffele was six shots behind even before he hit a shot at the Tour Championship under the new scoring format.
His goal was just to be focused, play good golf and see where he stood in the FedEx Cup play-off finale.
The cameras following his every move on the back nine at East Lake were the first hint it was going well.
The leaderboard on the 18th green confirmed it.
"I saw I was in first," said Schauffele, who won here two years ago to become the PGA Tour's Rookie of the Year. "Happy with the day."
The American did not come close to a bogey in a six-under 64 that was the best score of Thursday's opening round by two shots.
But it was worth only a share of the lead with Justin Thomas and Brooks Koepka in a tournament where players started with better scores to par than others depending on their Cup standings.
Schauffele could have enjoyed the sole lead, but he missed a five-foot birdie at the last, which left him fired up.
"As weird as it sounds, I'm happy I missed that last putt so I'm not super satisfied with the round," he said. "I'll go out tomorrow with a little bit of vengeance."
Thomas, who started at 10-under and a two-shot lead as the No. 1 seed, was still among the leaders despite having trouble finding the fairway.
That was the least of his problems on the back nine. He hit a pitching wedge into the water for double bogey and missed a pair of three-foot putts for a 70.
Koepka, the third seed who started three shots behind, birdied three of his last four holes for a 67 to join the leaders at 10-under.
Thomas said: "To come in (to) the house at 10-under feels pretty good. I thought I played better than I scored.
"I played a lot of good golf the last five or six holes, other than that dumb mistake on No. 15. I still can't believe those two short putts."
Rory McIlroy, five shots back at the start as the No. 5 seed, had a 66, one shot behind at nine-under.
Over the next three days, it should feel like a normal tournament. The score to par is all that matters in deciding who wins the Cup and the US$15 million (S$20.8 million) prize.
It was setting up to be a shoot-out. The top five were separated by five shots at the start. After one day, 12 were within five of the lead.
ASSOCIATED PRESS, REUTERS