Carl Pettersson shot an opening round 62 to take early control of the Wyndham Championship in Greensboro, North Carolina.
Pettersson's eight under par effort at the Sedgefield Country Club maintained his recent run of good form and gave him a one-shot lead over David Mathis and South Africa's Tim Clark.
In the final PGA event before the FedEx Cup play-offs, Pettersson's effort was only one shot off the course record he set himself in 2008.
Swedish-born but a resident of nearby Raleigh, Petterson produced a streak of four consecutive birdies to give him hope of equalling his own record - but he missed his opportunity at the last hole.
Petterson's first round at a club where he is a member continues his impressive run.
The 34-year-old won the RBC Heritage in April, while Sunday's third-place finish at the USPGA Championship was his fifth top-10 finish of the year.
Mathis, who has missed his last four cuts, will be encouraged by his round of seven birdies, while also a shot off the pace is Clark - who had an eagle at the fifth and followed up with five more birdies.
Tom Gillis, Scott Stallings and Troy Matteson all shot 64s, while Matt Every was on his own on five under after a first round which contained a double bogey five at the seventh.
A cluster of 12 players were a shot further back on four under par - including Webb Simpson. However, the US Open champion's card was marred by a bogey at the 11th.
The first round was dominated by Americans, with only three of the top 19 coming from outside the United States - Petterson, Clark and India's Arjun Atwal, who is one of 12 players four shots off the pace after a 66.
There were more nationalities represented on three under - 10, to be precise - with Angel Cabrera, Trevor Immelman, Nicolas Colsaerts, Sergio Garcia and England's Gary Christian among them.
However, on a day when most of the field scored well, South Korea's Sung Kang had a round to forget.
He was six over after seven holes, with a triple bogey seven starting the decline in a round which saw him finish 10 over par.