Matt Kuchar posted his second straight 70 on Saturday and that gave him a 2-stroke lead after three rounds of the Memorial Tournament.
Kuchar, who earned his fifth PGA Tour title earlier this year, ended 54 holes at 8-under-par 208.
Kevin Chappell matched the low round of the day with his 4-under 68. That helped him jump into a share of second place at minus-6. Kyle Stanley managed a 1-over 73 to end alongside Chappell in a share of second place.
Second-round leader Bill Haas struggled to a 4-over 76. He fell into a tie for fourth place at 5-under 211. He was joined there by Matt Jones (70) and 2010 champion Justin Rose (71).
Charl Schwartzel had the lead early in the third round, but played the final 11 holes in 6-over par. He stumbled to a 4-over 76, that left him tied for seventh with J.J. Henry (68), Scott Piercy (71) and Adam Scott (69).
Tiger Woods played the back nine first in round three and carded an 8-over 44. He got one back with three birdies and two bogeys on the front side as he shot 7-over 79. Woods shares 69th place at 8-over 224.
The 44 Woods shot was the worst 9-hole score of his career. He had shot 43 on three previous occasions.
The second round was completed earlier Saturday after being suspended by darkness on Friday. Players went off split tees in threesomes for the third round to beat forecasted thunderstorms.
Woods, the defending champion, stumbled to double-bogeys at 12 and 15. After a bogey at 17, he faltered to a triple-bogey at 18 to fall to plus-8 for his round and 9-over par for the tournament.
Around the turn, Woods birdied the first and second. After a birdie on the par-5 fifth, he tripped to a bogey at No. 6. Woods closed with a bogey at the ninth.
"It was a rough day. It was tough out there from beginning to end," Woods said through a PGA Tour media official. "We didn't hit that many bad shots starting out the day and the next thing you know we are quite a few over par. It was a tough day. I tried to fight back on the back nine, it just didn't quite materialize."
Haas led Schwartzel by one to start the round. Haas dipped into a share of the lead with a bogey at the fourth. He dropped another shot at eight. On the back nine, Haas got one stroke back with a birdie at 11, but he followed with three consecutive bogeys from the 12th to slide to minus-5.
Kuchar birdied the fourth and seventh to move to 8-under, but he was two behind Schwartzel, who had birdies at five and seven.
Schwartzel's 2-shot lead over Kuchar was cut in half when the South African failed to save par from a bunker on the par-3 eighth. Kuchar followed with a bogey of his own on the ninth to dip two back.
There was a 2-shot swing at the 10th. Kuchar, playing one group ahead of Schwartzel, converted a 19-footer for birdie to move to 8-under. Schwartzel joined him there as he again couldn't get up and down for par from a greenside bunker.
Schwartzel faltered to a third bogey in four holes as he found water with his second shot at the 11th. That bogey dropped him to 7-under.
Kuchar, last week's runner-up at Colonial, bogeyed the par-3 12th, but bounced back with a 12-foot birdie putt at 13 and he followed with a 17-footer for birdie at 14. Those birdies gave Kuchar a brief 3-stroke lead.
The 2011 runner-up found water with his second shot at the par-5 15th. That led to a bogey, which dropped Kuchar back to minus-8. He parred the last three holes.
"I played some steady golf. I got the wind figured out as best as possible and I'm driving it well," Kuchar stated in a TV interview. "You can play some moderately aggressive golf out there."
Schwartzel continued his slide down the leaderboard with a 4-putt double bogey at the 13th. That included three putts from inside five feet. He also bogeyed the 15th to drop into a share of seventh.
Chappell ran off three consecutive birdies from the fifth to jump to 5-under. Around the turn, he tripped to a bogey on the 11th, but birdied Nos. 13 and 15 to gain a share of second at minus-6.
Stanley had three bogeys and a birdie on the front nine. He wrapped bogeys at the 10th and 12th around an eagle on the par-5 11th. Stanley birdied the 15th to get back to minus-6 and he parred the last three to share second.
NOTES: The start of the final round was pushed to 10:40 a.m. (ET) as strong storms were in the forecast overnight. Players will play in threesomes and go off both the first and 10th tees ... Kuchar lost the 54-hole lead at Colonial last week and that dropped him to 1-1 when owning the 54-hole lead ... Woods' 79 also matched his career-worst score in a non-major.