Tiger Woods entered the championship fray at Pebble Beach with a third round 66 to move into US Open Championship contention behind Graeme McDowell and Dustin Johnson.
World Number One Woods, starting at four over par - seven strokes behind Northern Ireland's McDowell - overcame a difficult start to his round on the front nine and then blitzed the supposedly more difficult back nine.
The 14-time Major winner, who had won the first of his three US Open Championships by 15 strokes at Pebble Beach in 2000, had been searching for similar form following an on-course struggle of late.
After carding three birdies and three bogeys on his front nine, Woods' struggles seemed to be continuing but he changed gears at the turn and delivered five birdies to come home in 31 for 66, closing birdie, birdie, birdie.
Woods had negotiated the difficult par three 17th with a big-breaking birdie putt to get to level par and then produced a brilliant second shot from the 18th fairway to inside 15 feet, from where he putted out to get to one under par.
Woods, though, was not getting carried away with his performance, despite the animated manner in which he had celebrated his closing birdies with caddie Steve Williams.
"It's a US Open, I made a couple of key saves for par on eight and nine and you've just got to hang in there and I did that," Woods said.
McDowell had begun his round at three under par with a two shot lead over Masters Tournament champion Phil Mickelson, two-time US Open Championship winner Ernie Els, Japanese teenager Ryo Ishikawa and American big-hitter Johnson.
The European Ryder Cup player from Portrush had looked to have been in trouble off the first tee as he found right rough but McDowell responded with a superb rescue shot over a small tree to give himself a birdie from three feet, getting to five under and a four shot lead with a follow-up birdie at the second.
Then came a bogey at the third, though, and when playing partner Johnson eagled the fourth, McDowell's lead had been cut to just one shot.
They were level pegging when Johnson birdied the sixth and then the American showed he was more than just a power player as he sent his wedge tee-shot at the 99 yard par three seventh to within a foot of the hole for another birdie and the outright lead.
The lead changed hands again at the ninth as McDowell birdied and his rival bogeyed before the American birdied the 11th to join the Northern Irishman in the lead at five under, four ahead of Woods.
Mickelson, a five-time US Open Championship runner-up, had blazed a trail with a second-round 66 that moved him into contention but he was quickly in trouble as he bogeyed his first two holes to slip to one over.
The World Number Two rallied with a birdie at the par three fifth but then double-bogeyed the par four ninth to fall to two over, scraping back another shot at 11 to return to one over.
Mickelson was not the only nervy starter on the leaderboard. Ernie Els, Paul Casey and Ryo Ishikawa all endured difficult starts on the Monterey Peninsula.
England's Casey, a co-leader after 18 holes, was within three shots of the lead when he began his third round, having posted a triple-bogey eight at the 14th on Friday. But he recorded another big number at the par four second, where he took a triple-bogey seven to drop to three over and he was four over after 12.
Els and Ishikawa also dropped strokes, the South African at level par after 11 holes, alongside Gregory Havret of France, who was two under for the day after 14.
KJ Choi of Korea and Alex Cejka of Germany were one over after 13 and 12 holes respectively while Mickelson dropped another shot at 12 to join the improving German Martin Kaymer and the struggling Ishikawa on two over.
