Tiger Woods had a roller-coaster round at the Buick Open in Michigan but still ended the third day with a one-stroke lead.
Woods began the third round with a four-stroke advantage but fell three shots behind by the midway point.
He then recorded three birdies on the back nine to finish a shot clear of Esteban Toledo.
Woods posted a one-under-par 71 to complete 54 holes on 15-under-par at 201.
His round included five birdies, two bogeys and a double-bogey seven on the first hole.
Fred Funk is tied for third with Bob Tway on 12 under par at 204, one stroke ahead of first-round leader Kent Jones and two in front of Steve Flesch, Tom Byrum, David Toms and Jim Furyk.
Toledo birdied five of the first nine holes to make the turn at five under, then birdied two of the first four holes on the back nine to get to seven under.
But Woods put the pressure on Toledo with birdies on the 12th and 13th and the Mexican relinquished the lead with bogeys on the 15th and 17th to finish with a five-under 67.