Ireland's Shane Lowry kept hold of the lead until play was suspended due to darkness after a weather-blighted day two of the RBC Heritage tournament in South Carolina.
The Clara man was a shot ahead and nine under overall with two greens to go when his round was truncated, leaving him three under through 16 holes at a stormy Hilton Head.
Lowry had picked up two shots before play was halted due to the weather at 12.48pm local time - and did not get under way again for another three hours and 43 minutes.
Returning from the lengthy interruption he carded a birdie on the fifth, although dropped a shot soon after on the 187-yard par-three seventh.
Lowry set off on an orderly return to the club house and picked up another shot on the 15th before play stopped for the day at 7.47pm.
Weather conditions are expected to be improved when he finishes off the round first thing on Saturday - with American Trey Mullinax vying to take over at the top of the leaderboard.
A shot behind him lie Emiliano Grillo and Dustin Johnson, who both shot 67s on Friday to rise into joint-third.
England's Ian Poulter also carded a 67 to rise into seventh on five under, tied with nine others including Antrim's Graeme McDowell, who had five holes left to play.
Tommy Fleetwood was tied for 18th on four under when play was suspended, but will also have five holes to improve his lot when play resumes.
Seamus Power got into the clubhouse with a 72 that left him two-under-par overall.