Rory Sabbatini made a flawless start to the RBC Heritage as a seven-under 64 earned him a two-shot lead in South Carolina.
Sabbatini rolled in seven birdies at the Harbour Town Golf Links and kept his card blemish free to end the opening day two clear of fellow Americans Matt Kuchar, Billy Horschel, John Huh and Chesson Hadley.
The 42-year-old South African, who won the last of his six PGA Tour titles at the Honda Classic seven years ago, defied a lower back problem as he covered the back nine in 31, including a monster 50-foot putt for birdie at the 14th.
Sabbatini picked up another shot at the fifth and then birdied his final two holes to set a clubhouse target that rarely came under threat for the remainder of the round.
Kuchar, who lifted the title on Hilton Head Island in 2014, was hot at the start and finish of his opener as he birdied the opening two holes and picked up three strokes in four holes to close out his 66.
Graeme McDowell and Paul Casey are among the PGA Tour stars paying tribute to Patrick Reed following his Masters victory last week
Big-hitting Scot Martin Laird led the British challenge on four under, although he took some shine off his 67 with his only bogey of the day at the 16th which dropped him into a share of sixth with Harris English, Jonas Blixt and Patrick Cantlay.
Dustin Johnson got to four under with six to play after following a back-nine 34 with three consecutive birdies from the first, but the world No 1 bogeyed three of his last five holes around one further gain at the eighth to begin with a frustrating 69.
English pair Ian Poulter and Matt Fitzpatrick are alongside Johnson on two under, with Poulter recovering from a mid-round blip which undid some fine early work which yielded birdies at two of the first three holes.
The Houston Open champion, who is playing his sixth straight tournament, made mistakes at the eighth and ninth before he got back on track on the inward half following a superb par save from 50 feet at the 10th after finding water from the tee.
Ian Poulter was happy with his opening 69 at the RBC Heritage which included a superb par-save from 50 feet midway through his round
Poulter birdied 15 and 16 and parred safely in to climb back into the top 20 along with Fitzpatrick, while two-time major champion Martin Kaymer salvaged a 69 with birdies at the final two holes.
But Harbour Town specialist Luke Donald, who has posted a remarkable five runner-up finishes in the tournament, will have his work cut out just to make the weekend after he littered his card with three double-bogeys in a five-over 76, while Paul Casey and Tyrrell Hatton were just a shot better off.