Gary Woodland will take a one-shot lead into the final round of the Farmers Insurance Open at Torrey Pines after difficult conditions saw much of the field struggle on day three.
With all players playing the tough South Course, Woodland fired a two-under par 70 to move to eight under, a shot clear of Australian Marc Leishman and overnight-leader Jordan Spieth who had to settle for a 75.
The day was even worse for defending champion Tiger Woods, who recorded a 79 to fall to six over and miss the secondary cut which was required to get the field down to 70 for Sunday.
The world number one was one under for his round after eight holes but back-to-back double bogeys followed by five consecutive dropped shots saw him tumble down the leaderboard and a birdie on the last was not enough to save him.
Woods, who has won this tournament seven times, missed a secondary cut for the first time in his career and the 79 was the joint-third highest round of his PGA Tour career.
At the other end of the standings, Woodland looked to be establishing a healthy lead before a shaky finish gave the rest of the field hope for the weekend.
The American hit birdies on the first, eighth, 10th and 14th to sit 10 under before recording a first dropped shot of the day on 15.
The 29-year-old regained that shot on 16 but a double-bogey on 17 saw him finish the day just a single shot clear of the pack.
Leishman was a picture of consistency as he recorded just a single birdie and bogey in his 72 and he believes that finding the fairways will prove key in the final round.
"The greens firmed up and got a little bit quicker and a little bit harder to roll in those putts," he told Sky Sports 4.
"With a few of the tough pins you take a little bit more of a conservative line but for the most part you're conservative round here anyway.
"Hopefully I can get the putts to drop tomorrow and see what happens.
"Through the middle of the round today I missed a few fairways in a row there and it's a tough place out of the rough so definitely hitting fairways is the key."
Americans Pat Perez and Morgan Hoffman were on six under after both got round in par and they were a shot clear of a large group on the congested leaderboard.
Amongst those on five under were Belgian Nicolas Colsaerts who fell back after firing a 75 and Andres Romero whose 67 was the low round of the day.
The Argentinian hit six birdies and a bogey to fire himself into contention.
The group at four under included Keegan Bradley, Jason Day and Scotsman Russell Knox while Ian Poulter was a further shot back.
Stewart Cink, who had been just a shot off the lead overnight, recorded a disappointing 79 to slip to two under and now looks unlikely to claim a first win since his Open Championship triumph at Turnberry in 2009.
Defending Open champion Phil Mickelson had earlier withdrawn from the tournament due to a back problem.