Two-time major winner Zach Johnson rolled in a five-foot birdie putt at the 18th on Thursday to seize a share of the first-round lead at the US PGA Tour Sony Open in Hawaii.

Johnson, the 2009 winner at Waialae in Honolulu, had seven birdies in his seven-under 63, joining early pace-setter Chris Kirk atop the leaderboard in the US PGA Tour's first full-field event of 2018.

Kirk, a four-time winner on the US tour, nabbed five of his seven birdies on the back nine. He had a look at eagle on the par-five 18th, where he holed a two-footer for birdie.

Johnson got off to a hot start in his pursuit of Kirk, with birdies at the first three holes. He added another birdie at the ninth, and after a near-miss at the 12th rolled in birdie putts of 24 feet and 21 feet at 13 and 14 to move within a stroke of the lead.

Johnson, winner of the 2007 Masters and the 2015 Open championship, broke away from the second-placed bunch at the final hole, despite finding a fairway bunker off the tee.

Johnson admitted his round was a pleasant surprise, after a bout of flu cost him some pre-season practice time.

"I came here later than I anticipated -- like four or five days later and I had zero expectations on my game," the 41-year-old said.

"That being said, sometimes it's nice, you just kind of go out there, find a rhythm and then just stick with it."

Kirk, whose most recent victory was at Colonial in 2015, said a return to his old putting routines had paid off on the greens.

"I'm kind of going back to some of the drills that I did four, five years ago when I was putting week-in, week-out really well, and trying to do those drills every day," Kirk said.

"I had a great day today, and I'm about to go do it. It takes about five or 10 minutes. It's laziness, I guess, not doing it consistently over the last couple of years."

The leading duo were one stroke in front of a group of four players on a crowded leaderboard.

Vaughn Taylor fired six birdies in his six-under 64 and was tied with Brian Harman, Kyle Stanley and Talor Gooch. Stanley capped his round with an eagle at the par-five ninth, rolling in a 41-footer.

Gooch rocketed out of the blocks with three straight birdies, finishing with eight birdies overall against two bogeys. Harman, playing in the afternoon, had eight birdies that included three in a row at the fifth, sixth and seventh.

Japan's Daisuke Kataoka and Americans Peter Malnati, Matt Every and Tom Hoge all shot 65.

- Spieth's quadruple misery -

World number two Jordan Spieth dropped back late with a quadruple-bogey eight at his penultimate hole -- the par-four eighth.

Spieth was rolling at four-under when he fired into a tree off the tee at eight. His next three shots also hit trees before he found a greenside bunker.

He rallied somewhat with a birdie at his final hole for a one-under par 69.

Defending champion Justin Thomas, who fired a first-round 59 in route to victory last year, had three birdies in a three-under 67.

World number four Thomas had Phil Mickelson's former caddie Jim "Bones" McKay on his bag, filling in for regular caddie Jimmy Johnson, who is sidelined by plantar fasciitis.

Source: AFP