Australian Adam Scott fired his lowest round of the season to take the first-round lead at The Players Championship on Thursday.
World number one Tiger Woods, by contrast, tied his worst round at the TPC at Sawgrass, slumping to a three-over-par 75.
Scott's seven-under 65 gave him a one-stroke lead over Duffy Waldorf and Kevin Sutherland. Waldorf ended his round in erratic fashion with an eagle, a double bogey and a birdie in the last three holes.
South Korea's KJ Choi, Thomas Bjorn of Denmark and Bob Burns were in joint fourth place on five-under 67. Burns was the only player among the leaders to enjoy a bogey-free round in the tournament widely regarded as the fifth "major".
Brandt Jobe, Scott Verplank, Spain's Sergio Garcia, Ernie Els of South Africa and Ireland's Padraig Harrington all recorded 68s.
Woods is now eight-over for his last four rounds and has not carded a round of par or better since his 67 in the Bay Hill Invitational last Thursday.
"I didn't think I played that poorly," Woods told reporters. "I hit a few shots in there close and didn't make them and when I needed a par putt early in the round, I didn't make those.
"I put myself in position to make putts and I made nothing, and then towards the end I made a few putts to keep me where I'm at right now."
Scott, 23, who was tied for third at Bay Hill last week, continued his fine form at Sawgrass with five birdies in the first nine holes and three more coming home. His only bogey came at the par-four 15th.
"I've really turned my game around," Scott said. "Not just this year but from the second half last year I have played pretty solid.
"It's just been steadily improving since then. So that's what I've said for the last year or so, I want to be more consistent."
Except for a missed cut at the Sony Open in Hawaii in January, the Australian has been consistent.
He has nothing but top-10s to his name, a seventh at the Mercedes Championship, a tie for ninth at the WGC-World Match Play Championship and his tie for third last week.
"I was just swinging the club terribly," Scott said of his performance in Hawaii. "It was long, it was loose, it was not in time, no rhythm, and I made it a struggle, obviously.
"So I had a week off and I thought about the swing a lot and spoke with (coach) Butch (Harmon) about it and went and worked, practised a lot harder," added Scott, who won the Deutsche Bank Championship last year as a rookie.
Defending champion Davis Love III ballooned to a five-over-par 77 on Thursday and may not play in the second round due to a recurring back ailment.