Defending champion Graeme McDowell produced a typically gutsy finish in tricky morning conditions to open with a level par 71 in RBC Heritage at Hilton Head.
The Rathmore man was three over par with just six holes to pay but birdied his 13th, 16th and 18th holes to finish the day just five shots behind leader Matt Kuchar, Scott Langley and William McGirt at Harbour Town Golf Links in South Carolina.
Starting at the 10th, McDowell had to scramble for par at the 14th, where he holed a 12 footer for his par three. But he then bogeyed the 16th, three-putting from 32 feet, and dropped another shot at the tough 18th when his second went into the hazard left of the green.
A poor drive at the third meant another dropped shot but he dug deep on the way home to haul himself back up the leaderboard.
At the 194-yard fourth he hit his tee shot to 14 feet and holed the putt and after missing a good chance from six feet at the fifth he then holed from off the green at the 195-yard seventh for another two to get back to one over.
A wedge to 10 feet at the ninth, followed by another good putt, got him back to level par for the tournament.
Kuchar, Langley and McGirt carded six under par 66s to lead by two strokes from Harris English with Masters runner up Jordan Spieth firing a 69 to finish the day in a huge logjam for fifth place.
Spieth was playing alongside US Ryder Cup captain Tom Watson, who shot a four over 75.