He had a three-stroke lead over Garrett Willis (64). Scott McCarron (64) was four strokes back, and Kevin Streelman (64) was another shot behind. Jerry Kelly (65), Bob Sowards (66) and Tim Clark (67) were 9 under.
But clearly, the day belonged to Pettersson, a Swede who went to high school in Greensboro, played collegiately at North Carolina State and serves on the tournament's board of directors.
"This is like his retirement fund," defending champion Brandt Snedeker said. "He plays good here every year."
A year ago, while speaking at the Wyndham's previous home, Pettersson voiced his support for the then-rumored switch to Sedgefield. He played the Donald Ross course for the first time in November, shortly before the move was made official.
Then, he began this year's tournament with a 64 and admitted afterward that he was "a bit edgy starting out" because "this is a home game for me."
This time around, those jitters were long gone.
"The courses (on the PGA Tour) have been set up hard, so it's a nice change to be really aggressive, and (Sedgefield) kind of suits my style," Pettersson said. "I try to play really aggressive all the time, and so far it's paid off great."
In matching the lowest single-round score on the PGA Tour this year, he shot a 30 through his opening nine holes. Six of his 11 birdies came on the front nine, and he set the tone with birdies on first three holes.
"As soon as I did that, my mind kind of set in and played nice all day," Pettersson said.
By the time Pettersson reached the par-5 15th, he confessed to catching himself daydreaming about shooting a 59
- and then promptly bogeyed the easiest hole on the course, sending his third shot into a greenside bunker.
He quickly recovered, sinking a 40-foot putt on the 16th for the first of two straight birdies. He had a chance to make it three in a row on the course's most difficult hole
- the 507-yard, par-4 18th - but rolled his birdie putt a foot to the right of the hole, tapped in for par and tipped his visor to the vocal hometown crowd.
"I was glad Carl ran out of holes," Willis said. "Every time I made a birdie, it seemed like he made one, too."
That remarkable round put him in position to contend for his third career PGA Tour victory and first since the 2006 Memorial.