(CNN) -- Tiger Woods had to settle for fourth place as Sean O'Hair clung on for a one-shot victory in the $6.4 million Quail Hollow Championship in North Carolina.
Woods is left frustrated again as a birdie attempt on the 12th narrowly misses.
O'Hair finished with a three-under 69 to hold off fellow Americans Lucas Glover and Bubba Watson, with the world number one a further shot back after a frustrating level-par 72.
Woods admitted afterwards that he is still looking to rediscover his best form after his comeback from knee surgery.
"I've been very pleased with some of my progress," he told the official Tour Web site www.pgatour.com.
"I'm also not so pleased with some of it," Woods added. "It's been spotty, streaky. I just need to get a little more consistent."
A wasted opportunity on the par-5 14th encapsulated Woods' performance on the final day as he closed with 10 straight pars when birdies were needed.
Having driven the green and with a makeable eagle putt to tie the lead, he made a hash of his attempt and needed to make a testing six-footer to avoid four putting.
"It was downwind and I saw George (McNeill's) putt roll out. I kept telling myself, 'This putt is faster than it looks. It's faster than it looks.' And I didn't heed my own warning," said Woods.
"The next one I blocked again. And I made a wonderful six-footer for my three-putt."
Woods uncharacteristically also missed other birdie chances but insisted his short game was in order.
"Well, that's all I did for months is chip and putt. So yeah, my short game is better than it has been in a while.
"I just need to get a little bit more crisp with my driving and my long irons and get that dialed in. My short irons are actually pretty good, it's just the longer stuff is not where I want it at all."
When Woods carded 65 to lead on the opening day, he looked set to score the second win of his comeback after claiming the Bay Hill title as O'Hair slipped up on the final day.
But it was not to be as O'Hair gained redemption despite bogeying the final hole as he three-putted.
World number two Phil Mickelson charged through the field on the final day for a superb 67 in the tricky conditions to finish a shot behind his arch-rival Woods in a six-strong tie for fifth which included England's Ryder Cup star Ian Poulter.
But overnight leader and former Masters champion Zach Johnson went the other way with a sorry four-over 76.
Attention now turns to the Players Championship at Sawgrass in Florida later this week, dubbed the fifth major and attracting the cream of the world's best golfers including Woods, Mickelson and defending champion Sergio Garcia.