PINEHURST North Carolina Martin Kaymer rebounded after making three early bogeys on a difficult day for scoring to lead the U.S. Open by five shots midway through the third round on Saturday.
The 29-year-old German, a commanding six strokes ahead overnight in the season's second major, conjured a miraculous eagle at the par-five fifth to offset some of the early damage and reach the turn in one-over 36.
That left him at nine under for the championship, with American Kevin Na and burly Zimbabwean Brendon de Jonge tied for second as Pinehurst's No. 2 Course firmed up under blazing afternoon sunshine.
Na, who won his only PGA Tour title at the 2011 Justin Timberlake Shriners Hospitals for Children Open, had completed nine holes and de Jonge, yet to win on the U.S. circuit, 11.
American Erik Compton, a double heart-transplant recipient, was at three under after 13 holes, level with Swedish world number two Henrik Stenson, after 11.
Tricky pin positions, many of them tucked away in the corners of the turtleback greens, and slick conditions presented a daunting challenge and only six players in the 67-man field were under par for the day.
Kaymer, seeking his second major title after winning the 2010 PGA Championship, made his first bogey at the treacherous par-four second where he three-putted from long range, just off the front of the green.
That dropped him back to nine under, but still six strokes in front after playing partner Brendon Todd also bogeyed the hole.
Kaymer narrowly missed a birdie opportunity from nine feet at the third, then did well to drop only one stroke at the par-four fourth after taking an unplayable lie when his tee shot ended up next to a pile of pine needles.
He punched a low third shot down the fairway, well short of the green, struck his fourth to 15 feet and coolly sank the bogey putt before pumping his fist with relief.
With his lead cut to five strokes, Kaymer appeared to be in trouble at the fifth when his tee shot sailed left into a native waste area behind a small bush.
From there, however, he brilliantly struck a high draw to six feet and sank the eagle putt to get back to 10 under, seven ahead of his closest pursuers.
Kaymer again stumbled with a three-putt bogey at the difficult par-three sixth, where his first putt rolled off the edge of the green, before he parred the next three holes to remain at nine under.
British Open champion Phil Mickelson, who has been a U.S. Open runner-up a record six times without ever winning the title, carded a 72 to end the third round at five-over 215.
"Interesting day," he told reporters after mixing three bogeys with a lone birdie. "A little different golf course. Pins were very difficult.
"But the greens were receptive, it wasn't unfair. It was a very good test. It was hard for me because I was trying to make a move and it was hard to get birdies."
(Reporting by Mark Lamport-Stokes; Editing by Julian Linden)