Jordan Spieth has no idea what it is like to play from behind at the Travelers Championship.
The defending champion led after every round last year in his first visit to TPC River Highlands, and a shot a 7-under 63 on Thursday to match Zach Johnson for the first-round lead.
Spieth had six birdies and an eagle out of the bunker on the par-5 sixth hole - a shot reminiscent of the green-side bunker shot that gave him a victory last year over Daniel Berger in a playoff.
"They've got some sort of magnetic sand for me," Spieth joked.
"But it was actually a pretty tough shot there, almost a little downslope and I had to hit close to the ball, which you just have to commit to it.
"I just hit the shot that was necessary. I probably could have gone 4-5 feet by, but I couldn't hit it any better than I did and I was obviously fortunate for it to hit the pin and go in."
Matt Jones is the best-placed Australian and shares sixth spot after carding a 65. Jason Day is a stroke further back at four under and in a tie for ninth.
Johnson went out in the morning and led for most of the day. He had eight birdies, including six straight on the back nine, one off the course record.
"Six in a row is a treat," said Johnson, who finished tied for 12th last week in the US Open at Shinnecock Hills.
"I had a lot of loft in my hand, lot of wedges in my hand. So that's kind of how you've got to think about it is you have a lot of opportunity on the back side if you get the ball on the fairway. There are some holes you can get at."
Rory McIlroy missed a 13-foot putt for par on the final hole that would have given him a share of the lead and finished in a three-way tie for third place with Brian Harmon and Peter Malnati.
Brooks Koepka followed his second successive US Open victory with a 68. Koepka, who started on the 10th tee, shot a 31 on his first nine, but bogeyed four of his final six holes.
The Travelers was selected by the PGA last year as its "Tournament of the Year" and the "Players Choice." That has helped attract a 156-player field that includes five of the world's top 10 ranked golfers and all four reigning major championship winners.