'It feels great,' said Petrovic. 'A lot of emotions going through me right now. That last putt seemed to take about 12 minutes to fall in. I saw every dimple rolling over and over and over.'
Petrovic and Driscoll returned to the par-5 18th tee at the TPC of Louisiana and Driscoll hit his drive into the left rough. Petrovic found the fairway off the tee and advanced his second shot down the fairway.
Driscoll muscled his second shot down the fairway and played a wedge to the front edge of the green. Petrovic then dropped his third shot 25 feet from the cup. Driscoll raced his birdie try 8 feet past the hole, while Petrovic rolled his within 5 feet. Driscoll's par putt missed to the right and Petrovic converted his par try for the win.
'After seeing his putt, I came up short,' said Petrovic. 'I just wanted to get in there and hit it before I started thinking about some other stuff. I cleared my mind pretty good. I was proud of myself because I was able to clear my head and step up and just hit it. I didn't think about anything. I said just hit it. You've made a million of these on the practice green, this one is a little harder, but it's still a putt, just go up and hit it.'
Petrovic was three shots behind DiMarco to start the final round and he had a solid front nine with back-to-back birdies from the par-5 second and back-to-back birdies starting at the par-4 sixth to make the turn at 13 under. Petrovic landed his approach inside 6 feet for a birdie at the par-4 10th and DiMarco followed with a bogey at the very same hole to forge a tie atop the leaderboard.
The duo exchanged pars over the next four holes with DiMarco playing in the group behind Petrovic. Petrovic three-putted for a bogey at the 15th to fall back to 13 under, but DiMarco failed to take advantage.
DiMarco hit his drive into a fairway bunker at the 15th and scrambled to a bogey of his own. Petrovic fell one shot back again with a bogey at the 17th, but his birdie putt at the last capped a round of 4-under 68 and gave him a shot at a playoff.
Driscoll had a chance to win outright in regulation after his third shot to the closing hole came to rest 5 feet from the cup. His birdie effort hit the hole, however, and he tapped in for a par. DiMarco then missed his par try to stay out of the extra session after a round of 72.
'I can gain some confidence out of today for sure,' said Driscoll. 'But it's kind of mixed emotions because I know I can play. But to not finish it off, just kills.'
Arjun Atwal posted his second straight round of 73 on Sunday to finish four shots off the pace at 9-under-par 279. Atwal was joined by Bo Van Pelt, Woody Austin and J.J. Henry in a tie for fifth.
Padraig Harrington, D.J. Trahan, Daniel Chopra, Richard S. Johnson and Chris Anderson shared ninth place at 8-under-par 280. Jay Williamson, Sean O'Hair and Brendan Jones were one shot further back at 7-under-par 281.
Vijay Singh, who was trying to win this event for the second straight year, managed a 72 in the final round to finish in a group at 5-under-par 283.