'I don't really know what to say right now,' admitted Pettersson, who pocketed $954,000 for the win. 'It feels fantastic. It hasn't quite sunk in yet. A real special day.'
'I'm pretty happy with myself to be able to get that done,' said Campbell, who won the Tour Championship two years ago. 'Winning is first, but to get myself into the Tour Championship...that was one of my main goals this week.'
Tag Ridings came into the week 126th on the money list with the top-125 retaining their cards after next week. He shot a 4-under 67 to tie for third and comfortably get inside the top-125.
'Next week, I get to go play my first golf tournament on tour without having to focus on making it inside the top-125,' said Ridings. 'I can just go out there and just play.'
Tim Herron (70) was also part of the group that tied for third and he, like Campbell, vaulted into the top-30 and will play at East Lake Golf Club next week.
Shigeki Maruyama, who bogeyed two of his last three holes on Sunday, and Geoff Ogilvy were bounced from the top-30.
Ridings and Herron were joined in third by Hidemichi Tanaka (67), Stewart Cink (67), Bo Van Pelt (70), Tom Pernice, Jr. (72) and overnight co-leader Steve Lowery (75). The group came in at 5-under-par 279.
Pettersson, who shared the top spot on the leaderboard with Lowery after the third round, had to overcome not just Campbell's late charge, but an early tie with Lowery.
Things changed quickly at the par-3 eighth. The two were tied and Lowery found a bunker off the tee. Pettersson was in a different trap and came up 30 feet short of the stick with his sand shot.
Lowery caught his ball thin and it flew over the green. His third shot did not reach the green, then his fourth ran 30 feet long. Lowery missed that putt for double bogey and finally tapped in for a triple, essentially knocking him out of the tournament.
Pettersson converted his 30-footer for par and had control of the tournament. At least until Campbell started making birdies on the back nine.
Pettersson, playing several groups behind Campbell, holed a 6-foot par save at the 10th to remain two ahead, but Campbell birdied the 11th and 12th holes to reach 6 under for the championship.
Campbell sank a 16-foot birdie putt at the 14th to get to 7 under and trail by one. He rolled in a 40-footer for birdie at No. 15 to join Pettersson in first at minus-8.
Campbell found trouble at the 16th when his drive landed in the left rough. He missed a 12-footer for par short to fall one behind. That margin was extended by Pettersson when he two-putted the 14th green for birdie.
It looked like the cushion would shrink when Pettersson badly missed the green right at the 15th. He hit a delicate pitch that stopped a foot from the hole and he tapped in the great par save.
'I knew there was a chance I could pull it off,' said Pettersson, referring to his spectacular shot at 15. 'But, I would have been happy with 10 feet past the hole.'
Campbell applied the pressure with an 11-foot birdie putt at the closing hole. Pettersson looked like he would give a stroke up at 16, but he holed a clutch 10-footer from the fringe to save par.
At the last, Pettersson ran his 21-foot birdie putt 3 feet by. He converted the par putt and become a first-time winner on the PGA Tour.
'It was a little easier in my dreams,' joked Pettersson, a Swede who has lived in the United States since he was a teenager. 'It's a fantastic feeling and tough to describe.'
Sean O'Hair (69), Jeff Brehaut (72) and Daniel Chopra (73) shared 10th place at minus-4.