Woodland, who could not manage a top-10 finish in his first 27 majors, looked as if he played for the biggest prizes in the game every week when he picked up two birdies on his outward nine and at one point increased his advantage to four strokes.
But a bogey at the eighth, his first in 34 holes, combined with a Justin Rose birdie dropped Woodland back to 10-under and a two-shot edge over the Englishman with a charging Brooks Koepka just one further back.
Woodland's nerve is sure to be put to the test over the closing nine with Rose hanging tough and two-time defending champion Koepka on the move.
Matt Kuchar, chasing his first major at the age of 40, and Chesson Hadley were four off the pace with Northern Irishman Rory McIlroy five back.
Koepka, bidding to become the first player in over a century to sweep three U.S. Opens, needed a few holes to get in gear before collecting back-to-back birdies at six and seven and another at the 10th to zoom into the thick of the hunt.
Mickelson and Woods, as always, were the Pebble Beach headliners and although they pulled in massive galleries, they gave their fans little to get excited about.
Woods, nine back to start the day, began his round in the same frustrating fashion that he ended the second round -- with a bogey -- and did nothing to improve his mood by picking up another at the third.
The early miscues appeared to fire up the 15-time major winner, and Woods responded with back-to-back birdies but the relief was only temporary as he gave back those two shots with bogeys at seven and 12.
Woods would birdie three of his final five holes, including the 18th but it was too little to late an even-par 71 leaving him at even par for the tournament and 10 behind the pacesetter Woodland.
"I got off to a crap start," summed up Woods. "I got off to an awful start, and clawed it around, but still gave myself a chance for tomorrow, which is positive."
While Woods at least walked off on a positive note, Mickelson signed off with a triple bogey.
Runner-up at U.S. Open a record six times and needing a victory here to complete the career grand slam, Mickelson will not get it done this year after signing for four-over 75 to leave him at three-over going into Sunday's final round.
(Editing by Clare Fallon)
