Atwal had a bogey on the fourth but soon after that he birdied the sixth, ninth and 10th before play was stopped on account of inclement weather. He was provisionally 40th at that stage.
Among other Asian names was KJ Choi (70) in tied 64th, while YE Yang was two-under through 16 holes. Harrison Frazar took the lead at seven-under 64 after a soggy and wet start to the FedEx Cup, as Hurricane Irene hit the area.
The event is expected to be hit heavily by the Hurricane and there is a strong possibility of it being cut short.
Vijay Singh and Jonathan Byrd shot 65 each, while Adam Scott, Charley Hoffman and Ryan Palmer had 66s and top seed Nick Watney opened with a 67 as 51 players did not finish their first round.
When play was stopped, William McGirt had seven birdies in an eight-hole stretch and he was seven-under through 11 holes.