Kevin Stadler teed off just after breakfast and finished right before dinner. It took him nearly 11 hours to complete a 7-under 64 at Liberty National.
And he still isn't guaranteed to be the first-round leader at The Barclays in Jersey City, N.J.
The PGA Tour's FedEx Cup playoffs got off to a soggy start Thursday with two rain delays that lasted six hours.
Stadler ran off three birdies early, then returned from the second delay and threw in four more birdies on a soft course.
Asked if it was difficult to stay mentally prepared, he replied, "I'm never really mentally prepared. Same as usual. It was all good."
Top-ranked Tiger Woods came out of the first delay by missing a short birdie putt on the par-5 13th and then making three straight birdies. He cooled slightly after the second delay for a 67.
Woods didn't mind the long day. He was more concerned about the next long day on the horizon.
Only the top half of the draw finished the round. The later starters -- Ben Crane played only two holes -- were to resume the round Friday morning and then go straight to the second round. That left the top half facing extra holes Saturday to get the tournament caught up.
"It was a long day, and tomorrow will be a short one," Woods said. "And then Saturday will be pretty much a marathon."
British Open champion Phil Mickelson and Masters champion Adam Scott were among those who didn't finish. U.S. Open champion Justin Rose shot a 68, while PGA winner Jason Dufner had a 71.
Camilo Villegas reached 8 under until back-to-back bogeys late in his round. He had a 65, along with Henrik Stenson and Ryan Palmer.
"Three breakfasts, three warmups, two lunches and a bunch of birdies, which is good," Villegas said.
Harris English was the low player who hadn't completed his round at 4 under through six holes.
LPGA Tour: Lydia Ko was back on top at the Canadian Women's Open.
The winner last year at Vancouver Golf Club at a tour-record age of 15 years, 4 months, Ko had a 5-under 65 at Royal Mayfair for a share of the lead with Angela Stanford and Christel Boeljon in Edmonton, Alberta. Boeljon had a hole-in-one on the 126-yard 16th.
U.S. Solheim Cup teammates Paula Creamer and Cristie Kerr shot 66s. Charley Hull, the 17-year-old coming off a strong performance in Europe's Solheim win, shot 69.