American Bubba Watson holds a one-shot lead going into the final round of the Deutsche Bank Championship in Boston.
Watson had been in a three-way share of the lead with Adam Scott and Charl Schwartzel but they fell a stroke and two shots behind respectively.
The American carded a one-under round of 70 to move to 11 under overall, hitting five birdies and four bogeys.
There is a five-way tie on 10 under while England's Luke Donald is two shots off the lead on nine under.
World number one Donald hit a three-under round of 68, with an eagle on the par five second aiding his challenge.
Watson had begun well with four birdies in his opening nine holes but a disastrous run of three bogeys in five holes, as well as a missed opportunity on the relatively easy par five 18th, meant his lead was not as significant as it could have been going into the final day's play.
"I gave away some shots today but made some putts," said Watson.
"I'll just go out tomorrow [Monday] and do what I've been doing. It's about staying focused, not worrying if a putt doesn't fall or somebody else starts really hot.
"If I was a couple back in the logjam I'd want to change something and step on the gas, but I'll just see what the course gives me and try to shoot lower than anyone else."
Scott was inches away from sharing his overnight lead after an outrageous 76-foot eagle putt at the last just slipped by and he had to settle for birdie and 10 under.
The group on that score also includes Scott's fellow Australian Jason Day, who rattled in an 18-foot birdie putt at the last for a 67 which was highlighted by an eagle at the second.
Brendan Steele eagled the last to match that round, and tidy 68s left Chez Reavie and Jerry Kelly level with the trio in second.
Scott added: "You've just got to see how it goes, hopefully get some momentum early on and you can ride it all the way round. Someone's going to have a low score out of this group near the top."
American Phil Mickelson shot 63 in the morning and is only four shots back.