Big-hitting Bubba Watson will take a two-shot lead into the final round of the Waste Management Phoenix Open at TPC Scottsdale.
The 35-year-old, who is still seeking a first victory since his 2012 Masters success at Augusta, added to his opening two rounds of 64-66 with a 68 on Saturday to finish on 15-under.
His four-under par round put him two clear of fellow American Kevin Stadler and three in front of Ryan Moore, Harris English and Japan's Hideki Matsuyama.
Watson had started the third round tied for the lead with Aussie Matt Jones and looked as if he might kick clear of the field after three birdies in his opening eight holes took him into a three-shot lead.
But a bogey at 10 after a plugged lie in a greenside bunker set the tone for a difficult back nine as he sprayed some loose tee-shots way off target and racked up a series of pars to allow the chasing pack to close in on him.
It looked as if he might lose his lead completely when he drove into a bush on the long 15th but a favourable ruling which afforded him a free drop allowed the Ryder Cup star to escape with a par and stay one clear.
Another loose tee-shot at the short par four 17th suggested his lead would remain just a single stroke but he played a lovely low chip which just had enough juice to creep onto the green and holed the birdie putt to give himself a little daylight.
A par at 18 secured him a two-shot lead going into Sunday.
"It was a struggle down the back nine but I held it together, made some key putts, made some key up-and-downs. I held it together, that's the part I like," said Watson.
"Got one more tough day but what I am seeing, building for the future, is it's coming together pretty good."
Second-placed Stadler, meanwhile, claimed a spot in the final group with birdies at five of the final six holes to shoot 67 and finish on 13-under. The son of Masters winner Craig will be seeking a first PGA Tour win on Sunday.
As for the trio on 12-under, Moore came home in six-under 30 to post a 64 while Matsuyama and English, whose par putt at the last horseshoed out, stayed right in the hunt with rounds of 68 and 69 respectively.
Phil Mickelson's outside hopes of a successful title defence completely vanished when he dropped three shots in the final three holes to card a one-over 72 and end the day 12 shots behind fellow lefty Watson.
Mickelson's attempt to send the 20,000 raucous spectators at the short par three 16th into a frenzy went wrong as he racked up a double bogey five after a poor tee-shot way left of the green and a fluffed chip which failed to reach the putting surface.
He did raise cheers though when he got in the Super Bowl spirit by hurling a series of American footballs into the crowd, suggesting he wasn't suffering too much discomfort from the troublesome back which saw him pull out of last week's Farmers Insurance Open at Torrey Pines.
Brendan Steele shot the low round of the day - a nine-under 62 - to vault up to tied sixth alongside joint halfway leader Jones and Hunter Mahan, the 2010 winner here.
Watch the final round of the Phoenix Open live on Sky Sports 4HD from 6pm. You can also see the live feed of the 13th, 16th and 18th holes from TPC Scottsdale on www.skysports.com/golf