South Africa's Trevor Immelman showed a welcome return to form by taking a one-shot lead after the first round of The Greenbrier Classic at The Old White in West Virginia.
Immelman shot three-under on each nine, carding seven birdies against one bogey, to post a 64 on the par 70 in White Sulphur Springs. It put him one clear of Americans Billy Mayfair, Derek Lamely, Webb Simpson and Gary Woodland, as well as Steven Bowditch of Australia.
Immelman, the 2008 Masters champion, has not had a top-10 finish since returning from surgery on his wrist 18 months ago but is confident he is nearing his best.
"I hope I'm close," Immelman told www.pgatour.com. "You never know with this game. It's been a frustrating couple of years not being able to swing the way I want to swing and practise the way I want to practise.
"I've definitely seen signs of improvement. Albeit slow progress, there's been progress. So I just keep trying to remind myself that I'm 31 and I've got a long way ahead of me. I'm just trying to stay patient and keep things going."
Pre-tournament favourite Phil Mickelson had five birdies in his opening round but carded five bogeys too on the way to a level par 70.
The left-hander, who finished joint runner-up in The Open at Royal St. George's, said failing to convert a series of makeable putts had cost him.
"It was a disappointing overall score for me, because I played well enough to score low. I missed six putts inside six feet, and I just can't do that," said Mickelson.
"I ended up making some longer ones, which was good, to offset it. But I've got to get this turned around for tomorrow."
Australian Stuart Appleby recorded a 71 on the opening day of his title defence.
The 40-year-old shot a spectacular final-round 59 to win the inaugural tournament 12 months ago but, with scoring harder, he finished the day seven strokes behind Immelman.
"Very different golf course. My score was very different. Of course a lot more difficult, a lot longer," said Appleby of The Old White TPC.
The stats backed that up. There were 41 rounds under-par on Thursday compared to 81 in the opening round 12 months ago.
Tom Watson, the Greenbrier's pro emeritus who skipped this week's US Senior Open in Ohio, could only return a five-over 75.